Made from rugged S2M tool Steel100% made in the U.S.A.Custom heat treated for strength and durabilityManufactured to tight tolerances to ensure accurate fit and full fastener engagementInsert bits have a retaining ring notch1/4" hex bodyFits all standard multi-bit screwdrivers and power drillsTamper-Proof Torx Bits have a retaining ring notch made from rugged S2M tool steel to fit all standard multi-bit screwdrivers and power drills. Their 1/4-in. hexagonal body is custom heat-treated to offer strength and durability, and is manufactured to ensure accurate fit and full fastener engagement.Torx is a registered trademark of Acument Intellectual Properties, LLC.