Dragon Single Flap Pet Door For Sash Windows
- Economical sash window panel with built-in single flap pet door
- Adjustable height ranges to fit windows 22" - 43" wide
- Easy and low-impact installation method
- Two-piece flap design improves sealing
- Sturdy aluminum framing available in black or white

Product Details
The Dragon pet door for sliding sash windows comes in seven different width adjustment ranges to fit varying window track widths. The spring-loaded design allows for quick and secure installation right into your window track. Featuring a two-piece flap design, the Dragon keeps the entire pet door opening sealed for maximum insulation value.
Features:
- Translucent, flexible flap easy for pets of all sizes to use
- Available in seven width adjustment ranges to fit sash windows 22" - 43" wide
- Two-piece flap design covers the entire pet door opening for improved sealing (for a double flap option see the Double Flap Dragon Sash Window Pet Door)
- Upgrade from a single to a double flap at any time by adding another flap assembly
- Single pane, tempered glass ideal for moderate climates
- UV-resistant additives in the flap and frame protect against warping and cracking in harsh weather
- Durable aluminum frame fits window tracks at least 1" thick
- Spring-loaded top piece for easy installation into your sash window track
- Includes a sturdy locking cover to block pet access when needed
Benefits:
- Allows pets the independence to come and go without cutting into your door or wall
- Simple, quick installation, easily removable—ideal for renters or vacation homes
- Flexible flap is safe and comfortable for dogs and cats to use
Size Chart
- Medium7 1/16"w x 13 1/16"h
- Large9 3/8"w x 16 9/16"h
Flap Dimensions:
7 1/16"w x 13 1/16”h
The entry way your dog goes through.

Height To Raise Window
21 5/8"
How high you must raise your window in order to fit the panel into the track.Flap Dimensions:
9 3/8"w x 16 9/16"h
The entry way your dog goes through.

Height To Raise Window
25 5/16"
How high you must raise your window in order to fit the panel into the track.Flap Size | Flap Dimensions | Step Over | Height to Raise Window | Recommended Pet Height* |
---|---|---|---|---|
Small | Coming 2023 | Coming 2023 | Coming 2023 | Coming 2023 |
Medium | 7 1/16"w x 13 1/16"h | 3 7/8" | 21 5/8" | 11" - 16" |
Large | 9 3/8"w x 16 9/16"h | 3 15/16" | 25 5/16" | 11" - 22" |
*measured from the ground to the tallest point of their back.
Installation Instructions

Parts
- 1 Sash Window Insert with a Pre-Installed Single Flap Dragon Pet Door
- 1 Foam Weather Strip
- 1 Locking Cover
Tools
- Flathead Screwdriver
Please read instructions & notes thoroughly before installation.
Step 1 Release Spring Mechanism

- Loosen the width adjustment locks at the end of the sash with a screwdriver. This allows the spring mechanism to move freely from side to side.
Step 2 Test Fit in Window Track

- Before applying weatherstripping, insert the sash into the window track to test he fit.
- Push into the spring mechanism and swing the opposite end into the opposite window track. Gently release then tighten the width adjustment locks.
Step 3 Apply Weather-Stripping

- Once you have confirmed the sash fits, loosen the width adjustment locks and remove it from the frame.
- Apply the foam weatherstripping by peeling back the paper and exposing the adhesive. Unroll it along the edge of the sash, pressing to ensure it adheres.
- Use scissors to trim the strip to fit the length of your sash. Apply to both the top and the bottom.
Step 4 Lock Into Track

- Place the sash back into the window, then tighten the width adjustment locks to lock it in place.
LOCKING YOUR WINDOW
For a temporary lock, place a removable wooden dowel or charley bar in either track above the window, shown here. For a permanent lock, install a screw in the track immediately above the window on both sides. You will no longer be able to raise the window.
FREQUENTLY ASKED QUESTIONS
What if my window is slightly too narrow?
The sash can be trimmed up to 3/4” in cases where it is a bit too wide to fit into the track. Remove the spring-loaded adjustment pieces using a #2 Phillips head screwdriver. Using a clamp and a flat surface, cut off the flanges using a jigsaw with a metal cutting blade. You can also use a hacksaw, though it is more labor intensive and you may end up with a less clean cut. The dark area marks where you can trim:
What if my window doesn’t open enough?
Some windows will have stops that prevent them from fully raising up. In some cases, these can be removed allowing it to go up far enough to get the sash in place. You want to be careful when removing them, as it could damage the window or void the window’s warranty.
What if the track is too narrow for the pet door?
The spring adjustment pieces are slightly wider than the rest of the pet door, which may prevent it from fitting in the track. There are several potential solutions. One, you can trim one of the flanges off the spring-loaded adjustment piece, turning the "U" shape at the end into an “L". Alternatively, you can remove just one of the adjustment pieces with a Phillips head screwdriver and add shims for a snug fit.
You could also use a small piece of board in the channel of the adjustment piece, shown here. This board can be thinner and extend into the track giving the tension you need to hold it in place. Last option would be to install the sash using brackets to screw it into the track. Brackets would need to be made or purchased from your local hardware store.
What can I do if the track is wider than the pet door?
If the track is too wide to support the sash upright, you can use foam weather stripping or shims inserted into the track on the sides and/or bottom to fill up any of the gaps causing it to wobble. For a more permanent option, you can toe nail the sash into the framing with screws.
FAQ
What's the difference between the single flap and the double flap pet door for window? The double flap option provides increased insulation against the cold. Both options have magnets on the flap to keep the door sealed in wind. For harsh climates, we recommend the double flap sash window insert. |
I want to get the large window dog door for my dog, but I am concerned about a person fitting through it. All Dragon Pet Doors come with a locking cover. This cover can be used to keep you doggy in. It also can be used to keep intruders from entering your home. It slides into the interior frame. |
How do I know what size Dragon Pet Door Sash is best for my dog? When installing the pet door you want it to clear the top of your dog's back by 1-2 inches, minimum. To give your pet the most comfortable pet door possible, make sure the step-over is less than 1/3 of your dog's height. You want the width of the door to be big enough to allow your pet to go through without touching the sides. Here's a pet measuring guide to help you out. |
Are replacement flaps available? Yes, you can buy Dragon replacement flaps. You can also use the replacement flap to upgrade from a single flap to a double flap on your dog sash insert at any time if you find you need improved weather resistance. |
Can my small and large dog share this pet door? Yes, but make sure to follow standard Measuring Guidelines. Make sure the size of the door is based off your tallest pet, but installed low enough for your smallest pet. |
Warranty
Dragon Pet Doors One Year Warranty
Dragon Pet Doors have a one-year warranty for normal wear and tear and manufacturing defects.
Customer Reviews

Size Chart
- Medium7 1/16"w x 13 1/16"h
- Large9 3/8"w x 16 9/16"h
Flap Dimensions:
7 1/16"w x 13 1/16”h
The entry way your dog goes through.

Height To Raise Window
21 5/8"
How high you must raise your window in order to fit the panel into the track.Flap Dimensions:
9 3/8"w x 16 9/16"h
The entry way your dog goes through.

Height To Raise Window
25 5/16"
How high you must raise your window in order to fit the panel into the track.Flap Size | Flap Dimensions | Step Over | Height to Raise Window | Recommended Pet Height* |
---|---|---|---|---|
Small | Coming 2023 | Coming 2023 | Coming 2023 | Coming 2023 |
Medium | 7 1/16"w x 13 1/16"h | 3 7/8" | 21 5/8" | 11" - 16" |
Large | 9 3/8"w x 16 9/16"h | 3 15/16" | 25 5/16" | 11" - 22" |
*measured from the ground to the tallest point of their back.

Parts
- 1 Sash Window Insert with a Pre-Installed Single Flap Dragon Pet Door
- 1 Foam Weather Strip
- 1 Locking Cover
Tools
- Flathead Screwdriver
Please read instructions & notes thoroughly before installation.
Step 1 Release Spring Mechanism

- Loosen the width adjustment locks at the end of the sash with a screwdriver. This allows the spring mechanism to move freely from side to side.
Step 2 Test Fit in Window Track

- Before applying weatherstripping, insert the sash into the window track to test he fit.
- Push into the spring mechanism and swing the opposite end into the opposite window track. Gently release then tighten the width adjustment locks.
Step 3 Apply Weather-Stripping

- Once you have confirmed the sash fits, loosen the width adjustment locks and remove it from the frame.
- Apply the foam weatherstripping by peeling back the paper and exposing the adhesive. Unroll it along the edge of the sash, pressing to ensure it adheres.
- Use scissors to trim the strip to fit the length of your sash. Apply to both the top and the bottom.
Step 4 Lock Into Track

- Place the sash back into the window, then tighten the width adjustment locks to lock it in place.
LOCKING YOUR WINDOW
For a temporary lock, place a removable wooden dowel or charley bar in either track above the window, shown here. For a permanent lock, install a screw in the track immediately above the window on both sides. You will no longer be able to raise the window.
FREQUENTLY ASKED QUESTIONS
What if my window is slightly too narrow?
The sash can be trimmed up to 3/4” in cases where it is a bit too wide to fit into the track. Remove the spring-loaded adjustment pieces using a #2 Phillips head screwdriver. Using a clamp and a flat surface, cut off the flanges using a jigsaw with a metal cutting blade. You can also use a hacksaw, though it is more labor intensive and you may end up with a less clean cut. The dark area marks where you can trim:
What if my window doesn’t open enough?
Some windows will have stops that prevent them from fully raising up. In some cases, these can be removed allowing it to go up far enough to get the sash in place. You want to be careful when removing them, as it could damage the window or void the window’s warranty.
What if the track is too narrow for the pet door?
The spring adjustment pieces are slightly wider than the rest of the pet door, which may prevent it from fitting in the track. There are several potential solutions. One, you can trim one of the flanges off the spring-loaded adjustment piece, turning the "U" shape at the end into an “L". Alternatively, you can remove just one of the adjustment pieces with a Phillips head screwdriver and add shims for a snug fit.
You could also use a small piece of board in the channel of the adjustment piece, shown here. This board can be thinner and extend into the track giving the tension you need to hold it in place. Last option would be to install the sash using brackets to screw it into the track. Brackets would need to be made or purchased from your local hardware store.
What can I do if the track is wider than the pet door?
If the track is too wide to support the sash upright, you can use foam weather stripping or shims inserted into the track on the sides and/or bottom to fill up any of the gaps causing it to wobble. For a more permanent option, you can toe nail the sash into the framing with screws.
FAQ
What's the difference between the single flap and the double flap pet door for window? The double flap option provides increased insulation against the cold. Both options have magnets on the flap to keep the door sealed in wind. For harsh climates, we recommend the double flap sash window insert. |
I want to get the large window dog door for my dog, but I am concerned about a person fitting through it. All Dragon Pet Doors come with a locking cover. This cover can be used to keep you doggy in. It also can be used to keep intruders from entering your home. It slides into the interior frame. |
How do I know what size Dragon Pet Door Sash is best for my dog? When installing the pet door you want it to clear the top of your dog's back by 1-2 inches, minimum. To give your pet the most comfortable pet door possible, make sure the step-over is less than 1/3 of your dog's height. You want the width of the door to be big enough to allow your pet to go through without touching the sides. Here's a pet measuring guide to help you out. |
Are replacement flaps available? Yes, you can buy Dragon replacement flaps. You can also use the replacement flap to upgrade from a single flap to a double flap on your dog sash insert at any time if you find you need improved weather resistance. |
Can my small and large dog share this pet door? Yes, but make sure to follow standard Measuring Guidelines. Make sure the size of the door is based off your tallest pet, but installed low enough for your smallest pet. |
Warranty
Dragon Pet Doors One Year Warranty
Dragon Pet Doors have a one-year warranty for normal wear and tear and manufacturing defects.
It is made very study and the looks of it is very pretty. I love the added window in the middle. Cats fit perfectly through it. The lock feature I use at night is very useful when they are inside. Thank you!
I have had a pet door in my window for years, it was homemade and seen it’s day, I ordered this one and am very pleased, it seems sturdy and has a nice clean look to it. Mine had a blemish on it and customer service was excellent. My dogs did have to get used to the window on one side, at first they were a little confused because the one we made was wood with door in the middle but once they realized that was not the door, they were fine. They are using it without any issues. I would give this a thumbs up, it doesn’t require any cutting into walls and if you want to take it out of window, no damage done. I am totally happy with this door.
I don’t have to worry about my cat out in the cold. He can come and go as he pleases. Best product I’ve invested in. I definitely highly recommend this product.
It took a while for my cat to get it but it works well. It is drafty but for what it is I think it’s pretty weatherproof. I did add more stripping and tape though.