Endura Flap Thermo Sash 3e Pet Doors for Sash Windows

45 Reviews
Regular price $603.00
Shipping calculated at checkout.

Color: White
Flap Size
Width Adjustment Range


  • Insulating sash window insert with built-in pet door for cats and dogs. From Small to XL flap sizes available. 
  • Suitable for windows 22" - 43" in width, with 1" thick track
  • Easy installation and semi-permanent, ideal for renters
  • Locking cover included that loads from the top
  • Video to explain how to measure sash window track width
  • Extra Large Flap 22" - 25" Width Panel is made with plexiglass, is custom-made-to-order, and is non-returnable
  • Custom orders are made to your specifications and are non-returnable

Product Details


The Endura Flap Thermo Sash 3e Pet Door for Sash Windows provides your pets with the freedom to come and go while maintaining your home's insulation and energy efficiency. This sash window insert features a built-in pet door, combining the elegance of a sleek frame with the reliability of a weatherproof, insulating panel.

The Endura Flap Thermo Sash 3e is designed to fit snugly into the track of most windows, with sizes available for windows ranging from 22" to 43" in width and at least 1" thick track. The easy-to-install, spring-loaded design ensures a secure fit without the need for permanent installation, making it an excellent choice for renters and vacation homes. Can't find your size? Order a custom width range to get a pet door panel tailor-made for your window. 

Crafted with a heavy extruded aluminum frame, the Thermo Sash 3e is available in white and dark bronze, blending seamlessly with your existing window. 

The heart of the Thermo Sash 3e is the flexible polyolefin polymer flap, designed to remain functional in temperatures as low as -40°F. Lined with magnets along the edges, the flap offers superior sealing, remaining shut during heavy winds and extreme weather conditions. Additional magnets can be added to increase weather protection, or you can remove the magnets entirely to make the flap easier for timid cats to use. 

For added security and insulation, a locking cover and weather stripping are included with the Thermo Sash 3e. The product also comes with a 90-day return policy and a lifetime warranty, giving you peace of mind in your investment.

Please note that the Extra Large Flap 22" - 25" Width Panel is made with plexiglass, is custom-made-to-order, and is non-returnable

Features:

  • Heavy extruded aluminum frame in white and dark bronze
  • Flexible polyolefin polymer flap, functional in temperatures down to -40°F
  • Superior sealing with magnets lining flap edges
  • Locking cover and weather stripping included for enhanced insulation
  • Lifetime warranty and 90-day return policy
  • Sizes to fit windows from 22" - 43" in width and at least a 1" thick track. Customized sizes available

Benefits:

  • Sleek frame and color variety are complementary to many windows
  • The flexible flap is easy for pets to use
  • Polyolefin polymer flap is pet and environmentally friendly
  • Accommodates both dogs and cats
  • Multiple pets can use the door due to its taller and slimmer design
  • Temporary/semi-permanent installation is perfect for renters and vacation homes
  • Keep your pets inside or out with the locking cover
  • Gives pets the ability to come and go when they please

Sizing & Fit

Size Chart

Flap Dimensions:

6"w x 11"h

The entry way your dog goes through.

Small flap
Small frame
Small rough cut

Height To Raise Window:

18 1/2"

How high you must raise your window in order to fit the panel into the track.

Flap Dimensions:

8"w x 15"h

The entry way your dog goes through.

Medium flap
Medium frame
Medium rough cut

Height To Raise Window:

22 1/2"

How high you must raise your window in order to fit the panel into the track.

Flap Dimensions:

10"w x 19"h

The entry way your dog goes through.

Large flap
Large frame
Large rough cut

Height To Raise Window:

26 1/2"

How high you must raise your window in order to fit the panel into the track.

Flap Dimensions:

12"w x 23"h

The entry way your dog goes through.

Extra Large flap
Extra Large frame
Extra Large rough cut

Height To Raise Window:

30 1/2”

How high you must raise your window in order to fit the panel into the track.

Flap Size Flap Dimension Outside Frame Dimension Recommended Pet Height
Small 6"w x 11"h 18 1/2" 9" - 15"
Medium 8"w x 15"h 22 1/2" 9" - 21"
Large 10"w x 19"h 26 1/2" 9" - 27"
Extra Large 12"w x 23"h 30 1/2” 9" - 34"

 

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

Customer Reviews
4.8 Based on 45 Reviews
5 ★
84% 
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4 ★
13% 
6
3 ★
2% 
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Filter Reviews:
DZ
08/10/2024
Darren Z.
United States United States

Electric Billed Significantly Reduced

We are loving this petdoor. My cats are slowly getting used to going in and out through this door rather than our sliding glass door. Now they have free range to enter the patio as they wish. We have removed the magnets to help them get used to it. My wallet is happy because now we do not need to to leave rthe sliding glass door open which causes the AC and/or Heater to run constatly driving up my cost. This is a very high quality product and better than many of the cheap competitors. Highly recommended!!!!

LB
08/04/2023
Lorrie B.

Great cat door

This cat door window was easy to put in. One of my cats still has a little trouble using it. Due to the fact she is somewhat skittish of anything different. Now the other one blew right through it. Less than an hour. He wanted to get in his new Catio!

NS
05/22/2023
Norma S.

Best in Class

I bought my doggie (window) type door back in January of 2022. It has been the best thing I ever did for my pomerianian. She learned how to use it and when I have to leave for a few hours I have peace of mind she is able to let herself out. Also, when I dogsit her son, he also has learned (from her his mom) how to go in and out the doggie door, so he is not peeing on my furniture in side the house, so no more doggie diapers either. It has been durable to this day. I installed it in a window and it juts right up to my back patio so all I had to do was add some bricks to make it easy for the dog's height. Don't wait! Get it!

PF
08/26/2022
Paul F.

Great pet door but the instructions were for a sliding glass door model not the sash window model. We figured it out but the correct instructions would have made it a lot easier!

So far so good!

CG
04/04/2022
Cynthia G.

Thermo Sash 3e Pet Door for Sash Windows

I bought this door for the catio I built outside a bedroom window and it is exactly what I was hoping for. Keeps the cold out and the cat happy. Being able to change which side the flap is on is a huge bonus. It's a well designed window/pet door and built to last. I'm very glad I bought it!