The General Tools wire gage is designed to accurately determine the thickness of non-ferrous wire and metals such as copper, brass, and aluminum Gage numbers are Americ Standard wire gage 0 to 36 Decimal equivalents of each size are stamped on the reverse side of the wirel gage This US standard wire gage is 3-1/4" in diameter and 3/32" thick Featuring a satin finished, this wire gage is made from hardened and tempered heavy gage steel