Ideal for small apartment buildings, offices, or condominiums, these aluminum 1250 series vertical mailboxes are SURFACE-MOUNT. Units come with a surface mount collar that is attached to the wall, which the mailbox unit is slid into and secured. They are constructed of durable, heavy-gauge extruded aluminum, with striated doors and sctratch-resistant trim. Each door measures 5-1/2"W x 16"H and a 6" depth. Each tenant door features a 5-pin cam lock with 2 keys, and a tenant name card holder. These units are USPS-Approved for RENOVATION OR REPLACEMENT ONLY. They are NOT approved for new construction. This unit features 4 doors and is a silver color.