PetSafe 4-Way Locking Interior / Exterior Cat Door

The 4-Way lock allows you to choose from four access options - open, locked, in-only and out-only. The open option allows entry or exit, locked option does not allow entry or exit, in-only option allows entry but no exit and the out-only option allows exit but no entry. It can be installed in interior or exterior doors or walls. An optional tunnel is included for installation in doors & walls 2" thick. Frame dimensions are 7 1/2" x 8 1/8" & flap opening is 6 3/16" x 6 7/8". Suitable for pets up to 15 lbs.