This CRL Security Tamperproof Screw Kit contains 20 of the most asked for sizes of machine and sheet metal Spanner Head Tamperproof Screws. It includes three matching Spanner Drivers and a total of 1,000 stainless steel screws in size #6, #8 and #10, in lengths from 1/2 inch (13 millimeter) to one inch (25 millimeter). It comes in a sturdy steel storage box. An ideal kit for institutions, schools, hospitals, etc. with security-type fixtures. Kit Contains 50 each of These Stainless Steel Screws: