The Multi-Flex Pet Door has 3 flexible panels, so your pets can go in and out without worrying about trapping their ears, paws or tails. Made of unbreakable polycarbonate, it also protects from the wind and is energy efficient. The locking slide keeps your pets where you need them. Easy to install in doors that are 1 to 1 3/4" thick. The optional Alarm Slide lets you know when your pet attempts to go through the door. Shipped directly from manufacturer. Please allow 7-10 business days for delivery.