12 piece set is made in the U.S.A. TORX® Plus bit sockets feature SK's high polish SuperKrome® finish, which provides for long life and maximum corrosion resistance. Through-hole design makes it easier to replace worn or broken bits: simply pop the old bit out and insert a new replacement bit. The new bit holder design is 9 times stronger and helps prevent the bit from slipping out of the socket while working. Bits are manufactured to rigid standards using high strength S2 steel. TORX® Plus bit sockets are designed for use on a new fastener found on today's vehicles in interior, trim and dashboard applications. The increased surface area of the new TORX® Plus fastener pattern allows 25% more torque on the fastener.