Copper alloy bar stock - Kawell USA bar stock comes in two sizes in order to be able to forge your own style and size of shoe needed in order to take advantage of all the antimicrobial and shock reduction benefits of using Kawell USA's EPA approved copper alloy. The bar stock lengths are: 5/16" x 3/4" x 30" (8x19x765 mm) and 3/8" x 1" x 36" (10x25x920 mm)