Pet Door Guys for Cats - "In The Glass"


  • Absolutely the best and most functional solution for glass doors for your bold cat
  • Dual pane glass custom made to your specifications and fits sliding and french doors
  • Features the energy efficient Endura Flap cat door
  • No room lost for you to get through and keeps the security of using your existing door lock
  • Steps: Glazier measures, you place the order on our site, the door ships to your glazier, they come out and switch your old glass out for the new glass with the cat door.

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Stock No: C02DD

Availability: In stock

Price From: $729.99
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Price From: $729.99

Pet Door Guys for Cats - "In The Glass"

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  • Absolutely the best and most functional solution for glass doors for your bold cat
  • Dual pane glass custom made to your specifications and fits sliding and french doors
  • Features the energy efficient Endura Flap cat door
  • No room lost for you to get through and keeps the security of using your existing door lock
  • Steps: Glazier measures, you place the order on our site, the door ships to your glazier, they come out and switch your old glass out for the new glass with the cat door.
Glass SizeCat Flap SizeFlap DimensionStock No
Standard Glass - Less than 34" x 76"Small #066" w x 11" hC02DDPS
Oversize Glass - Up to 46" x 92"Small #066" w x 11" hC02DDPO

The Pet Door Guys: Cat Door In the Glass

The best way to install a cat door through your existing sliding glass door frame is by replacing the glass with a Pet Door Guys unit! The new glass will have a cat door installed at the bottom, and you’ll be able to use your sliding glass door like normal. A glass professional will be needed to come measure your current glass and later swap it out for the new glass that has the cat door. The cat door that is used is the energy efficient Endura Flap, which is an insulating, flexible flap perfect for extreme weather. The flap system is extremely durable and carries a 15 year warranty.

How to Order

  • First, check that one of the installation options is suitable for you (see the Placement Guide for a more detailed explanation of the options). They are:
    • 2 Panel Slider: Installation in either side of the inside track panel. When using the center-post side, it's important to ensure that the screen will not interfere with the action of the cat door flap.
    • 3 Panel Slider: Installation may be in either side of inside track slider or jamb side of 3rd panel. The same concern applies to the screen as above.
    • 4 Panel Slider: Installation may be on either side of either inside track panel
  • Review How to Measure Your Cat to choose the appropriate size opening for your cat. The unit will have a minimum 3 3/4" step-over height in addition to your existing frame, so be sure to take that into account!
  • Engage a local glass shop willing to do the measuring and installation. The glass shop installer disassembles your sliding glass door (a very easy job), takes width, height and thickness measurements then re-installs your glass slider. He completes his portion of the Order Form.
  • Read our Detailed Information Page to get more specific information about how this works. Be sure to share this information with the local glass shop. If the installer has questions have them contact us directly and we can answer any specific questions they may have.
  • Purchase the product. Your total for merchandise, shipping and any sales tax will be shown. Charges from your local glass shop are not included, so you would pay your installer separately.
  • We then arrange with the factory to custom-build a new piece of glass with the cat door in the lower corner that you specify. We have that unit shipped to your glass shop.

At your convenience the glass shop installer returns to your home, uninstalls your glass panel and replaces it with the new panel containing the cat door.

You are responsible for payment to the glass shop for the measurement and install. We will charge you only for the cat door. In our experience, the cost for these two service calls will likely be between $120 and $200 but you may want to establish this cost in advance.

More Important Info

  • Click here for more information about LoE glass.
  • The vinyl framing is available in white or beige and that's what you're choosing in the drop down product select. The cat door framing comes only in white.
  • Because this is a custom order all sales are final.
  • Glass that is 34" x 76" or smaller is considered "standard" size.
  • Glass that is larger than 34" x 76" is considered "oversize".
  • You can get an approximation of your actual glass size right now by measuring the "daylight" dimension (just what you can see) and adding 3/4" in both dimensions. This is NOT accurate enough to order the product.
  • Allow about 3-4 weeks plus transit time for delivery.

Customer Reviews

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  • Fantastic review by Betty
    5 5 Fantastic

    Love this! We took a gamble living in Canada and had it shipped to a U.S. Address and picked it up. Our glass installer measured for the order and installed it today. We love it! So glad to get the full width of the door back. The panel was good but this is amazing. When we saw it we weren't sure it would work. It comes not as just a pice of glass but a glass in a frame that fits into your door frame. Very minimal reduction in view. Genius really. Thank you!!!

    (Posted on 9/21/2016)

  • Excellent Product review by Louise
    5 5 Excellent Product

    Excellent product. Extremely happy . Wish I had found this company years ago. Great craftmanship. Thank you.

    (Posted on 2/15/2015)

  • excellent product review by bob
    5 5 excellent product

    I am a carpenter and did the install myself. went together without a hitch. the finished product is beautiful and works flawlessly. great design

    (Posted on 11/4/2014)

  • Awesome! review by Fantastic!
    5 5 Awesome!

    Wish I would have done this much sooner. We couldn't be happier with our purchase. No more squeezing between a removal panel. No more drafts. Love it.

    (Posted on 10/28/2014)

  • "In The Glass" review by SG in Virginia
    5 5 "In The Glass"

    I absolutely love this door in the glass. Now my patio door opens, shuts, and locks normally again. All my friends are very impressed when they see it. We tried the panel insert first, but our patio door is fairly small (3 foot wide slider), so the panel didn't leave much of an opening for us. So we really needed the "in the glass" feature. Fit and finish on the "in the glass" door (and the panel door too) are flawless. We have owned several pet doors over the years and these are definitely top of the line pet doors. Definitely worth the price, especially when the winter wind howls, the magnetic edge really holds it closed. Our previous pet doors did not stay closed when the wind blew.

    (Posted on 7/13/2013)

  • Great Door review by Lorrie
    5 5 Great Door

    We purchased our door a couple of months ago and we love it. It is so much better than the panel door we had before. My husband installed it himself and it fit perfectly.

    (Posted on 7/6/2013)

Weight 3.0000
Manufacturer Pet Door Guys
Your Maximum Pet Size Cats
Climate Suitability Severe-4 Season
Sealing Value Very High
Wind Resistance Very High
Frame Material Vinyl
Employs Patented “Endura Flap” Yes
Insulation Value High
Possible to Add Additional Magnets for Greater Wind Resistance Yes
Flap Material Engage
Flap Design Single, One Part , Flexible, Insulated Flap
Flap Colors Clear
Flap Thickness 7/8"
Award Winning Design Yes
Replacement Flaps Available Yes
Flap Warranty (if separate) 15 years
Locking Cover Material Dimensional ABS
Ability to Lock Flap Separate Locking Cover-Loads from Top
Can Be Installed In Dual Pane Glass Sliding Glass Door, Sash Windows, Sidelight, Sideways Sliding Windows, Single Pane Glass Sliding Glass Door, Vinyl-Framed Sliding Glass Door
Warranty Period 1 year
Return Period Not Returnable
Manufacturer's Restocking Fee Product is final sale, no return

What is an "In the Glass" Cat Door?


Pet Door Guys

products offer Endura Flap™ exclusively. Here's why -

Design of the Endura Flap


Q: What is Low “E” coating?

A: It stands for Low-emissivity coating. Low E is applied to the inside of the glass to cut backon the heat and cold transfer. Low outside temperatures combined with moist, warm air inside the house can result in condensation on the inside of any glass window including that in a patio door. Dual pane, low "E" glass can greatly reduce or eliminate this problem. This feature is especially important in cold climates.

Q: What does it mean by standard and oversize glass size?

A: Standard Glass Size has a square inch range of 34" x 76" or smaller. Oversized Glass Size would be any range over 34" x 76" and up to 46" x 92". Both work with Single or Dual Pane Tempered Glass.

Q: When I purchase a “Through the Glass” dog door, is the entire sliding glass dog door included?

A: No, when you purchase a “through the glass” dog door it comes with the glass panel only. The framing of the sliding door is NOT included in the purchase. Since this unit will replace your current glass inside your framing, there will be an installation process you or a hired professional will need to follow.  As well as filling out the appropriate order form.

Through the glass pet doors are a great option!

Q: How long does it take to get the “Through the Glass” models?

A: It takes about 2-3 weeks for these type of pet doors to be manufactured, then allow 1-5 business days for transit time from the west coast. When it ships out we email you the tracking information, so you’ll know when to expect delivery and can schedule for an installer to come out.

Q: Why is it so expensive to solely purchase the pet door?

A: “Through the glass” units can be pretty expensive because you’re getting a custom unit made entirely to your specifications, that’s why we highly recommend hiring an installer to get all of the measurements, as these custom doors are non-returnable. Some of the extra options can add to the cost as well, say if you need the Low E coating or added tint.

Q: What are the benefits to the through glass units?

A: The "through the glass" units don't take up the space for you to walk through like a patio panel pet door would.  This is a huge benefit if you have a smaller retrofit slider, as now you don’t have to worry about trying to squeeze through sideways.  Additionally, the "through glass" doggie doors utilize your existing lock, so you will not have to worry about how to go about securing your home.

Through the glass vs. patio panel

In terms of appearances benefits, it also utilizes your current door frame, so you don't have to worry about matching a new frame with your current door and frame. The constantly open sliding glass door will leave you with extra framing blocking your view outside! When in the glass, you do not experience this issue. The Endura Flap Pet Door included is great for insulation so it compliments the dual pane glass in most new sliders.  

Through the glass vs. Patio Panel

Q: Why can't I just cut into any glass door or window?

A: You can not just cut into any glass or window because their are different types of glass that require different procedures to properly cut or replace.  If you attempt to cut into "tempered" or dual pane glass, it will shatter. So how do you tell if your glass is tempered? Tempered glass usually has an indicia, or 'bug' as it is called in the trade, in one corner of the glass panel. If you see a bug, the glass is tempered. If you don't see a bug, well.... it may be plate glass, which you can cut, or it may not. Older houses are more likely to have plate glass; newer houses probably have tempered. We always like to recommend hiring a professional when it comes to cutting or installing glass units. Cutting glass on your own is a health and safety risk.

Q: Can you walk me through this process of ordering the through glass units?

A: First, you’ll want to go over all the information located on the “details” tab of the product you chose and make sure to check out the Placement Guide which will show you where the pet door should be installed based on your current sliding glass door situation.

Next, you will want to Review Sizing Suggestions, Adding Step-Over, and After Installation in order to find the appropriate size opening for your pet.  Make sure that when you do get an installer that you give them all this information too, so that they are able to correctly fill out the order form that they will send to us.

Next you purchase the product via our PetDoors website, and we hold the order for you until we receive that order form. Your total for merchandise, shipping and any sales tax will be shown for the glass unit, however the charges from your local glass shop are not included since you would pay them separately.

You will then need to contact a local glass shop to have them do the measuring, installation, and filling out of the order form. The installer will come out and take apart your sliding glass door frame (a very easy job), takes width, height and thickness measurements then re-installs your glass slider. After that they finish filling out their portion of the order form.

That completed Order Form needs to be emailed (or faxed) to use. Our email is .

Once we have the order placed and the form we fax it over to the manufacturer so they can build the unit!

We ship the completed through glass dog door directly to the installer and they come back out and switch the current unit for the one with the dog door.  Done!

Q: Can I install one of the glass units myself?

A: Depending on how handy you are it might be possible, although it is not the best idea to DIY because they are custom ordered, so you can’t return them if the measurements are off.  We highly recommend that you have a glass company do it for you, unless you are a trained professional.

Q: Do you offer electronic options for “Through the Glass” pet doors?

A: Yes, the SureFlap Microchip Pet Door and the Cat Mate Elite 355 Super Selective Cat Doors can be installed through the glass. However, these two options are not specifically made for a through glass installation and depending on your glass type would require replacing it or cutting it.  On the other hand, the Pet Door Guys pet door option is specifically made for a through glass installation and comes with the glass framing and the panel, but is not an electronic door option.

    You can still have an electronic pet door!                                                         The framing is included!

Glass around Pet Door Separate                                       Glass Framing around Pet Door Included

SureFlap Microchip Pet Door                                                        

Cat Mate Elite 355 Super Selective Cat Doors                         Pet Door Guys

Q: What is the minimum step over on the “Through the glass” units?

A: The minimum step over on the through glass units is 3 3/4" plus however tall the frame of the the sliding door is.  So if your frame is 2” tall than the minimum step over would be 5-¾”.  There are 2" or 4" step over add-on options as well, these will add 2” and 4” to the minimum to raise the step over to accommodate taller pets.  

Q: What is the largest flap size on the through glass units?

A: The largest flap size offered for through the glass units is XL 12" x 23".

Q: I have a small pet, only 10" to the shoulder and 15Lbs, will the small work?

A: Yes it should work, just be sure that the step over isn't too high for your pet.  For both of the manufacturers the minimum step over would be calculated by measuring the frame of the sliding door from the bottom to the start of the glass then adding 3-¾”.  So if your frame was 2” high then the step over would be 5-¾”. With a small pet at 10” we typically would recommend step over range of 3”-4”. A step over of almost 6” would make it much more difficult for your pet to get through, so reducing the step over as much as you can to get it into that range should be a main concern for you.  Typically you could use a step or a ramp for this.

Q: Does the flap in the glass units insulate well?

A: Yes, the Pet Door Guys glass units use the Endura Flap, which provides excellent insulation.

Q: Can you change the flap in the glass units if it wears out?

A: Yes, you can purchase replacement Endura Flaps on the website, it might sound strange, but you will need to purchase the one for the Door/Wall Mount since that includes the hole plugs.  However, they can be a little difficult to replace because you must remove the whole frame in order to get the new flap into place properly.

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Pet Door Guys

guarantees it will repair or replace any Pet Door Guys product which is found to be defective in material or workmanship and will pay the costs of repair or replacement to the original owner for a period of one year. Insulated glass is warranted for life against seal failure. This warranty is subject to the following terms and conditions:

  • This guarantee is offered only to the original owners of single family homes who purchase a Pet Door Guys product in the United States. It is not transferable and terminates upon sale of the home and does not apply to re-installation at a second location.
  • The warranty does not extend to commercial applications.
  • Pet Door Guys is not responsible for glass breakage, failure due to misuse, applied tints or films, any customer alterations to the product including painting, improper installation or acts of nature including fire, flood or earthquake.  Pet Door Guys is not responsible for natural weathering of exterior finishes or corrosion in highly corrosive environments.
  • Pet Door Guys is not responsible for incidental or consequential damage beyond our control. Pet door openings imply some risk. No guarantee is offered or implied regarding suitability or security against intrusion or unwanted entry or exit.