It’s a super simply way to keep cats separated during the introduction process while still allowing you to easily come and go from the room. 
 
It installs in seconds – read the installation options and choose one that allows for the strap to be adjusted to a short enough length to keep the cat out. Just peel and stick to the door and door frame, using the strong 3M adhesive included. You can adjust the width of the door opening to work with the size of your cat or kitten. Compatible with a variety of door types (Bi-fold, pocket, double.) Easy to use: Simply lift the hook/latch for quick and convenient access to the room. Made in the USA.