These SPECIAL ORDER recessed Mounted 4C Horizontal Mailboxes are U.S.P.S. Approved and manufactured to USPS-STD-4C Specifications. PLEASE NOTE: SPECIAL ORDER 4C MAILBOXES HAVE AN INCREASED COST AND LEAD TIME COMPARED TO POSTAL PRODUCTS UNLIMITED’S NORMAL QUICK-SHIP LINE OF 4C MAILBOXES. These boxes are ideal for apartments, commercial buildings and residential developments, and are required for new construction and major renovations. The indoor-use boxes are constructed of heavy duty aluminum and stainless steel hardware. They feature a durable powder coated finish available in aluminum, bronze, gold and sandstone. Doors include a heavy duty cam lock with a dust/rain shield and 3 keys. When planning your project, be aware the U.S.P.S. standard 4C requires a minimum of 1 parcel locker for every 10 tenant compartments. Parcel lockers must be a minimum of 15" H to meet the 1:10 ratio. Once this ratio has been met, smaller parcel lockers may also be added. Fully integrated and stand-alone parcel lockers vary by model. Most units include a compartment for outgoing mail collection and is labeled “Outgoing Mail”. The Outgoing mail compartment / carrier access door includes the U.S.P.S. master lock access door (lock installed by the U.S.P.S.) and cannot be used for mail distribution. Outgoing mail compartment includes a 10-3/4" W x 3/4" H mail slot and weather protection hood. This unit measures 16.375”W x 37.5”H x 17” and features a pull-down mail collection door the unit is a large collection hopper for OUTGOING mail only. Identical to Salsbury Industries part number 3710S-1C