Made entirely of rust-free aluminum, features an extruded body with a die-cast front door and rear cover. Door is attached with a full-width stainless steel hinge allowing for smooth operation. Durable powder coat finish. Adjustable red signal flag and magnetic door catch. Approved by the U.S.P.S. 7-1/2"W x 20-1/2"D x 9-1/2"H.