Ideal Pet Products Aluminum Sash Cat Flap Pet Door Small White 1.25" x 27" x 10.63"

[This review was collected as part of a promotion.] Window cat door arrived in tact and was very easy to install. Fits snuggly onto window sash using foam strip underneath to block any drafts or openings. The only reason this is not getting 5 stars is that the weather stripping to be used on top of the insert was not wide enough to block the gap between the upper and opened lower window. We ended up using a piece of pipe insulation to block the gap. A section of styrofoam pool noodle is also useable. We also cut a piece of PVC pipe to insert in the window track to keep the lower window from being able to be lifted up as a security measure. It took a little while for our cat to adjust to using the door. Prior to that we had inserted a piece of cardboard with a door size hole in it to see if our cat would use the opening to go from the house to the screened porch and if the regular cat door size would be large enough for him. He used this easily so we ordered the window. We used treats and showed him how to push the door open. He was hesitant to push the door open with his head so we would hold it open for him to go through, lessening how much we would open it every day. He took to using the door unaided to enter the house in 2 days. However he remained hesitant to use it to go out without assistance. Using pieces of tuna as enticement and continuing to partially open the door for him he slowly decided he could use it to go out after a little over a week and after 2 weeks has no problems using the door in either direction.