Ultraflex Pet Door - Extra Large (White) (14"H x 18.5"W) Color: White Size: 14"H x 18.5"W Medium Flap Size: 6 5/8"H x 11 1/4"W Extra Large Flap Size: 10 1/4"H x 15 3/4"W Features inner telescoping frame that adapts to doors of 1" to 1 3/4" thickness.