Gaines Keystone Signature Series Mailbox In White/Polished Brass Signature Keystone Series Mailboxes. Featuring stunning, raised solid brass US Mail letters Keystone Mailbox Collections are die cast from aerospace-grade, rust-proof aluminum Ultraviolet inhibitors protect the surface making it resistant to chipping, scratching, fading USPS Postmaster Approved. Made in USA Mailbox Measures 12 ? H x 10 3/8 W x 20 1/8 D