• Premium aluminum-frame pet door designed for sliding glass doors with tracks at least 1" thick
  • Removable spring-loaded panel for effortless installation and removal—perfect for rentals and vacation homes
  • 3/16" clear safety glass, 59% thicker than standard, enhances energy efficiency and durability. Prefer Low-E glass? Explore our Dual Pane Thermo Panel
  • Flexible polyolefin polymer flap withstands temperatures down to -40°F, with three-sided magnetic closure for superior wind resistance
  • Locking cover included for controlled pet access when needed
  • Includes SlideLock pin style locking mechanism that affixes to the slider frame for security
  • Available in white, black with custom sizes for the perfect fit
  • Adjustable step over height for a more natural pet entry

Endura Flap Thermo Panel 3e

The Insulated Patio Panel Built for Wind and Cold

301 Reviews
Made in the USA USA flag icon
Regular price $836.00

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Lifetime Warranty

Color: White
Flap Size
Height Adjustment Range



Enjoy secure, insulated pet access through your aluminum sliding glass door with a heavy duty aluminum panel, thicker safety glass, and a wind resistant Endura Flap system that installs cleanly without permanent construction.

  • Premium aluminum-frame pet door designed for sliding glass doors with tracks at least 1" thick
  • Removable spring-loaded panel for effortless installation and removal—perfect for rentals and vacation homes
  • 3/16" clear safety glass, 59% thicker than standard, enhances energy efficiency and durability. Prefer Low-E glass? Explore our Dual Pane Thermo Panel
  • Flexible polyolefin polymer flap withstands temperatures down to -40°F, with three-sided magnetic closure for superior wind resistance
  • Locking cover included for controlled pet access when needed
  • Includes SlideLock pin style locking mechanism that affixes to the slider frame for security
  • Available in white, black with custom sizes for the perfect fit
  • Adjustable step over height for a more natural pet entry

Installation & Fit

Designed specifically for aluminum sliding patio doors with track width at least 1 inch.
Compatible with standard recessed tracks and monorail track configurations.
Monorail installations use a dedicated adapter to integrate the panel more cleanly.
Fits within standard sliding door track height ranges with a built in 3 inch adjustment span.
Available in short, regular, tall, and custom panel heights to match a wide range of patio doors.
Installs as a removable panel without cutting into your existing door or wall.
Includes a SlideLock pin style lock that affixes to the slider frame for added security.
Alternative locking options are available for customers who cannot drill into the frame.

Best Suited For

Ideal for:

  • Aluminum sliding patio doors with track width at least 1 inch
  • Monorail track setups using the monorail adapter
  • Homes that want pet access without cutting into doors or walls
  • Windy or colder conditions where a magnetic sealing flap helps reduce drafts
  • Rental or vacation properties where a removable panel is preferred
  • Buyers who want the option to lock the pet opening when needed
  • Larger pets that benefit from taller flap options

Not ideal for:

  • Sliding doors with track width under 1 inch
  • Andersen or Pella sliding doors without modification
  • Vinyl patio door tracks (We recommend the Endura Flap Vinyl insert or Severe Weather Vinyl insert instead
Product Details

Product Details


The Endura Flap Thermo Panel 3e is built for pet owners who want a premium sliding door pet door without permanent construction. It installs as a vertical insert, so your patio door remains intact while your pet gets reliable, everyday access.

This model is designed specifically for aluminum patio doors with a track width of at least 1 inch. It also works with monorail tracks, using an adapter that helps the panel integrate properly with that style of frame. If you have an Andersen or Pella slider, this panel is not directly compatible without modification, so it is best treated as a special fit case before you commit. 

At the center is the Endura Flap, made from a flexible polyolefin polymer that stays functional in temperatures as low as minus 40 degrees Fahrenheit. The three sided magnetic closure helps the flap return to position after each pass, reducing drafts and holding firm in gusts up to 50 miles per hour for improved comfort in windy conditions.

The glass section uses 3/16 inch clear safety glass to add rigidity and insulation compared to thinner inserts. Combined with the aluminum frame, the result is a sturdier, more finished panel that is designed to hold up to daily use by pets of many sizes.
Looking for a Dual Pane glass option? Look no further - We offer a Dual Pane Thermo Panel 3e

For security and controlled access, the panel includes an interior locking cover for the pet opening, plus a SlideLock pin style lock that affixes to the slider frame. For homes where drilling into the frame is not an option, alternative locking mechanisms are available, including PetSafe Patio Door Lock.

If you want sliding door convenience with a stronger seal, heavier construction, and a premium feel, the Thermo Panel 3e is the core insulated Endura option built around performance and long term use.

Size icon Sizing & Fit

Size Chart

Flap Dimensions:

6"w x 11"h

The entry way your dog goes through.

Overall Panel Width

10 3/16"

How wide your panel is.

Flap dimensions
Panel width
Step over height

Step-Over Height

3" - 4 1/2"

The distance from the bottom of the panel to the bottom of your flap.

Flap Dimensions:

8"w x 15"h

The entry way your dog goes through.

Overall Panel Width

12 1/4"

How wide your panel is.

Flap dimensions
Panel width
Step over height

Step-Over Height

3" - 4 1/2"

The distance from the bottom of the panel to the bottom of your flap.

Flap Dimensions:

10"w x 19"h

The entry way your dog goes through.

Overall Panel Width

14 1/4"

How wide your panel is.

Flap dimensions
Panel width
Step over height

Step-Over Height

3" - 6"

The distance from the bottom of the panel to the bottom of your flap.

Flap Dimensions:

12"w x 23"h

The entry way your dog goes through.

Overall Panel Width

16 3/8"

How wide your panel is.

Flap dimensions
Panel width
Step over height

Step-Over Height

3" - 6"

The distance from the bottom of the panel to the bottom of your flap.

Flap Dimensions:

14"w x 27"h

The entry way your dog goes through.

Overall Panel Width

18-3/8"

How wide your panel is.

Flap dimensions
Panel width
Step over height

Step-Over Height

3" - 7.5"

The distance from the bottom of the panel to the bottom of your flap.

Flap Size Flap Dimension Step Over Range Outside Frame Dimension Recommended Pet Height
Small 6"w x 11"h 3" - 4-1/2" (ships at 3") 10 3/16" 9" - 15"
Medium 8"w x 15"h 3" - 4-1/2" (ships at 3") 12 1/4" 9" - 21"
Large 10"w x 19"h 3" - 6" (ships at 4-1/2") 14 1/4" 9" - 27"
Extra Large 12"w x 23"h 3" - 6" (ships at 4-1/2") 16 3/8" 9" - 34"
XX Large 14"w x 27"h 3" - 7.5" (ships at 6") 18-3/8" 9" - 41"

Do not know which size to get? Here is a measurement guide to help you out.

Track Height Adjustment range is based on the measurement of your sliding door track height from the lowest point of your track to the highest point. Each Endura Flap Thermo Panel 3e has a 3" adjustment range. Review our Track Measuring Guide video for additional, detailed information The following standard adjustment ranges are available:

  • Short: 74 3/4" – 77 3/4"
  • Regular: 77 1/4" – 80 1/4"
  • Tall: 93 1/4" – 96 1/4" (additional cost)

If your measured track height does not fall within one of the ranges above, we can make a custom height! Custom height option may take up to 4 weeks to special order the glass and build the panel.

Installation Guide

Installation Information

One-Piece Panel

Installation icon Printable Version
Installation icon Difficulty Easy
Installation icon Steps 10
Installation icon Time Required 0.5 hours

Parts

  • Panel Pet Door
  • Foam Weather Strip
  • Center Post Weather Seal Draft Stopper
  • Sliding Door C-Clamp Lock
  • Flathead Screwdriver

Tools

  • Flathead Screwdriver

Please read instructions & notes thoroughly before installation.

Step 1 Loosen Height Adjustment Locks

Loosen Height Adjustment Locks
  • Loosen the height adjustment locks at the top of the pet panel with the screwdriver. This allows the spring mechanism to move freely up and down.

Step 2 Test Fit the Panel in Your Track

Test Fit the Panel in Your Track
  • You want to put the pet door in your track before applying any weather stripping to ensure it fits. If the panel fits well, proceed to the next step. See the Troubleshooting Section if you encounter difficulties.
  • To insert the panel into the top track, push up against the spring mechanism and swing the bottom of the panel up and over the threshold.
  • Seat the panel on top of the small guide rail in the track.
  • If you can't quite get it in the track, try swinging in from the outside as the outside track wall may be shorter.

Step 3 Adjust Step-Over Height (Optional)

  • The Endura aluminum sliding door panel has a patented Adjustable Step-Over feature which allows you to adjust the height of the flap to the most comfortable fit for your pet.
  • Adjusting the step-over requires tools that are not supplied. You will need a Phillips-head screwdriver, and we recommend using a power tool if available, as the screws were tightly installed to hold the panel together during shipping.
  • The top of the flap should be positioned to be at least 1” above the top of the pet's shoulder.
  • If the factory setting is not suitable, please adjust it before proceeding. Otherwise, proceed to the Installation Instructions section.

Step 4 Remove the Screws (Optional)

Remove the Screws (Optional)
  • Lay the entire panel on a flat surface.
  • Using the Phillips-header screwdriver, or selected power tool, remove the bottom side-screws and loosen the upper side screws.

Step 5 Adjust the Spacers (Optional)

Adjust the Spacers (Optional)
  • Once the bottom screws have been removed and the upper side-screws loosened, the Pet Door Assembly and spacers can be removed by sliding the sections down and out of the panel.

Step 6 Reconnect the Pieces (Optional)

Reconnect the Pieces (Optional)
  • Replace the spacers and the Pet Door Assembly by sliding them back in a different order to achieve the desired height. You can move the spacer below and above the flap to raise or lower the flap height.
  • It is critical that the bottom piece is placed at the base. This is the designated attachment point for the screws.
  • Make sure that the locking cover side of the flap frame is on the same side as the height adjustment locks.

Step 7 Retighten the Screws (Optional)

Retighten the Screws (Optional)
  • When finished, replace the bottom side-screws and tighten the next upper-side screws.
  • A lower step-over height is easier for pets to navigate. However, if the top of the flap is low enough that the pet needs to crouch to get through their pet door, they can injure themselves and possibly cause the pet door to malfunction. If your pet door does not sit at a comfortable height for your pet, you may need a larger flap size.

Step 8 Apply Weatherstripping

Apply Weatherstripping
Apply Weatherstripping
Apply Weatherstripping
  • Once you're sure the panel fits, remove it from the frame and lay it on its side on the ground.
  • For foam weatherstripping: Peel the backing off the foam weatherstripping. Press it along both edges of the panel, trimming as needed with scissors to ensure a snug fit.
  • For rubber weatherstripping: Clean the edge of your sliding door or window with rubbing alcohol to help the weatherstripping stick properly. Starting at the top or bottom, peel and press the strip into place with the folded edge facing indoors—align angled cuts if you have two pieces. For best results, apply the seal to the sliding door or window, but it can go on the pet door panel if needed.
  • Foam weatherstripping is applied onto both sides of the panel, but the rubber weather stripping only applies on the side of the slider door. Your panel will come with one type of weather stripping. You do not need both types.

Step 9 Install the Draft Stopper

Install the Draft Stopper
Install the Draft Stopper
Install the Draft Stopper
  • The center post weather seal strip (draft stopper) should be installed on the inside of the home.
  • It can install on either the back edge of the sliding door panel or the leading edge of the stationary panel.
  • This strip prevents air from leaking between the sliding glass door and the stationary panel.
  • Trim with scissors as needed. Clean the edge of your patio door with rubbing alcohol before installing to assure a good seal.
  • Repeat step two to install the panel in your track.

Step 10 Install the Panel

Install the Panel
  • If you haven't already, insert the panel back into your sliding door track the same way you did earlier: pushing up against the spring mechanism and swinging the bottom into place. Push it snug into the side track!
  • Make sure everything is sitting securely.
  • Tighten the height adustment locks in the spring mechanism.
  • And that's it! Your pet door is installed and ready for use. Now, watch your pet strut through their new door like they own the place!

Two-Piece Panel

Installation icon Printable Version
Installation icon Difficulty Easy
Installation icon Steps 11
Installation icon Time Required 0.5 hours

Parts

  • Top Glass Panel Section
  • Bottom Flap Section
  • Foam Weather Strip
  • Center Post Weather Seal Draft Stopper
  • 4 Flathead Screws
  • 1 Flathead Screwdriver
  • 1 Sliding Door C-Clamp Lock

Tools

  • Flathead Screwdriver

Please read instructions & notes thoroughly before installation.

Step 1 Adjust Step-Over Height (Optional)

  • The Endura aluminum sliding door panel has a patented Adjustable Step-Over feature which allows you to adjust the height of the flap to the most comfortable fit for your pet.
  • The top of the flap should be positioned to be at least 1” above the top of the pet's shoulder.
  • If the factory setting is not suitable, please adjust it before proceeding. Otherwise, proceed to the Installation Instructions section.

Step 2 Adjust the Spacers (Optional)

Adjust the Spacers (Optional)
  • Simply slide the pieces up and out from the bottom half of your panel to rearrange.
  • Loosen a bottom screw if the pieces are too snug to move.

Step 3 Reconnect the Pieces (Optional)

Reconnect the Pieces (Optional)
  • Replace the spacers and the Pet Door Assembly by sliding them back in a different order to achieve the desired height.
  • You can move the spacer below or above the flap to raise or lower the flap height.

Step 4 Retighten the Screws (Optional)

Retighten the Screws (Optional)
  • It is critical that the bottom piece is placed at the base. This is the designated attachment point for the screws. You can now assemble the patio panel.

Step 5 Align the Connectors

Align the Connectors
Align the Connectors
Align the Connectors
  • Remove the 2 flat head sectional connector screws from the exposed part of the connector on each side.
  • Align the aluminum connectors extending from the bottom flap panel section with the top glass panel section.
  • Press the aluminum connectors into the holes at the bottom of the top glass panel section.
  • Ensure locking cover & height adjustment locks are on the same side.

Step 6 Assemble the Panel

Assemble the Panel
Assemble the Panel
Assemble the Panel
  • Gently tap the bottom surface of the panel against the ground to completely insert the connectors.
  • Protect hard surfaces to prevent scratching.
  • The components of the panel are designed to slide together very tightly.
  • Fasten the two panels together using the four flathead screws.
  • Use the included flathead screwdriver to tighten all four flathead screws so the two halves of the door are pulled together.

Step 7 Loosen Height Adjustment Locks

Loosen Height Adjustment Locks
  • Loosen the height adjustment locks at the top of the pet panel with the screwdriver. This allows the spring mechanism to move freely up and down.

Step 8 Test Fit the Panel in Your Track

Test Fit the Panel in Your Track
  • You want to put the pet door in your track before applying any weather stripping to ensure it fits. If the panel fits well, proceed to the next step. See the Troubleshooting Section if you encounter difficulties.
  • To insert the panel into the top track, push up against the spring mechanism and swing the bottom of the panel up and over the threshold.
  • Seat the panel on top of the small guide rail in the track.
  • If you can't quite get it in the track, try swinging in from the outside as the outside track wall may be shorter.

Step 9 Apply Weatherstripping

Apply Weatherstripping
Apply Weatherstripping
Apply Weatherstripping
  • Once you're sure the panel fits, remove it from the frame and lay it on its side on the ground.
  • For foam weatherstripping: Peel the backing off the foam weatherstripping. Press it along both edges of the panel, trimming as needed with scissors to ensure a snug fit.
  • For rubber weatherstripping: Clean the edge of your sliding door or window with rubbing alcohol to help the weatherstripping stick properly. Starting at the top or bottom, peel and press the strip into place with the folded edge facing indoors—align angled cuts if you have two pieces. For best results, apply the seal to the sliding door or window, but it can go on the pet door panel if needed.
  • Foam weatherstripping is applied onto both sides of the panel, but the rubber weather stripping only applies on the side of the slider door. Your panel will come with one type of weather stripping. You do not need both types.

Step 10 Install the Draft Stopper

Install the Draft Stopper
Install the Draft Stopper
Install the Draft Stopper
  • The center post weather seal strip (draft stopper) should be installed on the inside of the home.
  • It can install on either the back edge of the sliding door panel or the leading edge of the stationary panel.
  • This strip prevents air from leaking between the sliding glass door and the stationary panel.
  • Trim with scissors as needed. Clean the edge of your patio door with rubbing alcohol before installing to assure a good seal.
  • Repeat step two to install the panel in your track.

Step 11 Install the Panel

Install the Panel
  • If you haven't already, insert the panel back into your sliding door track the same way you did earlier: pushing up against the spring mechanism and swinging the bottom into place. Push it snug into the side track!
  • Make sure everything is sitting securely.
  • Tighten the height adustment locks in the spring mechanism.
  • And that's it! Your pet door is installed and ready for use. Now, watch your pet strut through their new door like they own the place!
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FAQ

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