Mailboxes 2204 Salsbury Aluminum Mailbox - 4 Doors - Rack Ladder SystemMailboxes 2204 Aluminum rack ladder system mailboxes for Private Access Keyed versions can be accessed by the U. S. P. S. when installed in rotary mail centers. Ideal for colleges, schools, private postal centers, corporate mail centers, military bases, government agencies and many other applications Units are 23 1 4" W x 12 1 8" H x 15 1 2" D Available with 5 different door sizes: (#1) 3 1 2" W x 5 1 2" H, (#2) 5 1 2" W x 5 1 2" H, (#3) 10 3 4" W x 5