Aluminum Letter Mail Door Plate Slot, Full Hinged Spring Loaded Flap & Back Plate, 3" X 13", Brass Finish #67107 Aluminum Letter Slot - Fluted Flap, Brass Finish Outside flap and inside frame Spring loaded single gravity flap Easy Surface Mount Installation, Screws Included Outside: 3" x 13", Inside opening: 1-5/8" x 11-1/2"