Wrapped stem 1/2”, Patch 3 1/8“ square (80 x 12 mm) 12 pcs and Wrapped stem 9/16", Patch 4" square (100 x 14 mm) 12 pcs For use in radial and bias ply tires. Designed for chemical or heat vulcanization. Patch and stem have gray vulcanizing gum with blue poly backing. Stem portion is wrapped with premium vulcanizing gum. Use with Carbide Burr Kit CB-M07 Wrapped stem 1/2”, Patch 3 1/8“ square (80 x 12 mm) 12 pcs and Wrapped stem 9/16", Patch 4" square (100 x 14 mm) 12 pcs