A TORX head lets you set a screw down tight without the bit slipping and damaging the screw slot. They give your work a clean, finished appearance. We've included T-10 and T-15 TORX sizes for use in different applications. T-10 gives you plenty of additional wall thickness where the head joins the shank; T-15 has a large socket that accepts the same driver supplied with many popular brands of rings and bases. You get an economically priced assortment of 240 screws, all made right here in the USA. 1 dozen each of 20 different screws; 11 Fillister Head and 9 Weaver Oval Head styles in 3 thread sizes and 4 lengths, all in a sturdy, compartmented box. For those special jobs we have incl Mfg: Brownells