Special Lite Products LB-998 Locking Insert for SCF-1003, SCC-1008, SCB-1005 and SCB-1015, Black Fits Classic, Floral and Hummingbird curbside mailboxes The bottom of the lock box is open 18 in. L x 6.75 in. W x 4.75 in. H (4 lbs) Maintenance free cast aluminum Powder coated finish