Mail Slot is made from solid brass material and is available in many finishes. Mail Slot has flaps on both sides of the door. The exterior is a spring-loaded flap and the interior is a gravity flap. Installation hardware is included making it quick and easy. Enhances the overall appearance of any Entryway. Hole size required: 2-3/4" x 11-5/8". Flap Opening: 2-1/8" x 11". Center to Center is 2 5/8" Horizontal and 11 15/16" Vertical.