A set of 4 inch long Torx drive PowerDrivers in size #15T. These are the best designed driver bits on the market. With a "Tamperproof" TORX RSC Tip. The RSC tips offers superior holding power and wear resistance. All bits are constructed of one piece magnetic "AISI-S1" Tool steel, with a reduced shank diameter for access in narrow applications. Eg: through electrical boxes, steel studs, automotive fasteners, heating and air conditioning devices, door and window frames and various fixtures. Including decking and construction. Also excellent for use on assembly lines with air drive or electric tools. These Tamperproof tips work in both standard Torx drives and Tamperproof drives. Whereas a standard Torx will not work in a Torx Tamperproof drive.