The Ruff Weather Pet Door is designed to provide an insulating barrier for hot or cold environments by using a dual flap pet opening at an economical price. The Ruff Weather Wall Mount will fit walls that are 4 3/4" to 7 1/4" thick. The frame is a heavy duty thermoplastic that has an approximate 2" profile. The security locking panel can be used on either the interior or the exterior side of the pet door. Pet Opening: 15 x 23 * Rough Cut: 16 1/4 x 25 1/2 * External Frame: 19 x 28 1/4 * Fits Walls: 4 3/4" - 7 1/4" in thickness