Big Horn 19395 12 pcs 7" Long Diamond Flat Files (140#, 200#, 400#). This is a set of 12 pieces Flat File that great for use on glass, rock, diamond, ceramic and other hardened steel and alloy. Soft plastic wrapped handle provide great grip. Each color of the diamond flat files measure 5/16", 1/4", 1/8" and 1/16" wide.