Fit my attic opening almost perfectly. Used staples per the directions then sealed it with duct tape to make it air tight. Before I could smell the attic and feel the heat. I have an older house with old insulation, and zero weather stripping on the attic door, and this has helped a lot.

The attic stairway insulator was easy to install and works great. Our attic pulldown opening is framed at 23 by 54 inches. The insulator is sized for a 23 by 56 inch space. In our installation there is about 5 inches of extra material at the end away from the ladder hinge. I folded this extra material and taped it closed at the bottom. Otherwise, the insulator fit fine. The zipper works easily. Staples were shot in every 4 inches to start, working from the stair hinge end first and the extra material was gathered at the other end and folded in half on the centerline. More staples were then installed every 1 inch, through the cloth edging to provide better strength than if shot through the aluminum foil only. Then aluminum ducting tape was added all around to close out all small gaps between the insulator and the 2 by 6 attic framing. The end result is a well insulated cover that is totally leak free during the heat of the Texas summer and cold of winter. With the house A/C set at 79 degrees F, the pull down stairs lower surface and wall temperature below the pulldown stairway dropped from 92 degrees F before the cover was installed to 80 degrees F after the cover was installed and the hallway air temp was 79 degrees F while the attic temp above the pull down stairs was 109 degrees F. These temps were measured with an handheld infrared sensor. This is a great improvement. Before the insulator was installed, you could feel a warm area in the hall under the stairs. I wish that I had installed this product 20 years ago when I moved into this house. The 1/8 inch gap around the pulldown stairs is now not leaking hot or cold air into the house. No more hot or cold air leaking into the house! Great product!

Easy install with an air stapler - just place the product, tack it every 6 inches or so (recommend making sure the product lays flat/vertical where door/spring mechanisms move during opening/closing), then go back and run a continuous line of staples. I ended up foil taping over my staples since I had the tape on hand anyway. Might help maintain R value.

My attic access is in a second floor bedroom that I am converting to a home theater. The room runs noticeably hotter (Texas summer) and the attic stair door does not seal the opening well.

Time will tell if this product makes a difference. I'll have hard data (ecobee temp sensor in the room).

Even while installing it, I could tell a huge difference in the heat that was able to come through. Comes a tad bit big but not an issue. Installs in less than 5 mins. I used roofing nails as another user suggested instead of staples.

Easy to install (took less than 10 minutes with an electric stapler) and traps air in the space. Seems to work well so far.