1/4" thick sheet aluminum, clear brushed anodized finish. Comes with wall thru liner / flange 8" (203).

Engraved "MAIL" or "LETTERS" is extra.

Dimensions:

Overall size: 13 1/2" X 5 (43.4cm X 12.7cm)

Opening size: 11" X 2 1/2" (27.9cm X 6.3cm)