PetSafe Freedom Aluminum Pet Door has a solid aluminum construction that installs easily and the soft, transparent single flap provides a tight weather seal. The Freedom Aluminum pet door includes a locking panel that gives you the power to control when your pets can use the door. Installs easily in any door thickness from 3/8" to 2". Flap opening: 5 1/8" x 7 5/8"; good for small pets up to 15 lbs. Shipping weight: 2 3/4 lbs.