Set contains Cat. Nos. 19542, 19543, 19544, 19545, 19546, TORX tip drives cut slippage, save fasteners, and transmit more torque to the work, Chrome plated shafts resist corrosion, TORX is a registered trademark of Acument Intellectual Properties, LLC, Klein offers a lifetime warranty on material defects and workmanship for the normal life of the product.