Aluminum Horizontal Mailbox Units (Wall Mount). 4 available two different sizes $1500 to $2000 depending on size. Ideal for apartment complexes, condominiums and other residential and commercial developments. Dimensions of the bigger ones are approximately 2 ft 10 and 1/2 in wide X 3 ft 3 in tall X 1 foot 4 in deep and it has 34 regular mailboxes and 1 box for outgoing mail, for a total of 35 boxes. Dimensions of the smaller ones are approximately 2 ft 4 in wide X 3 ft 3 in tall X 1 foot 4 in deep and it has 27 regular mailboxes and one box for outgoing mail, for a total of 28 boxes. See pics for a better description.