Stainless Steel Cleanroom Sterile Phillips Screwdriver 304 & 316 SS Stainless Steel Anti-Magnetic Sterile Cross X Head Phillips Screwdriver 316 & 304 SS L 1mm measurement is the blade length.Length is the measurement is the overall length. Zapworx range of Stainless Steel Phillips Screwdrivers can be purchased individually or as a kit set.