Made in the USA, Proto hand sockets incorporate the TorquePlus? driving system. This allows the socket to contact the fastener away from the corner while dispersing stresses over a larger area. This feature allows up to 15% more torque to be applied, whilst reducing the risk of corner rounding. This characteristic meets aerospace specifications, and all metric sockets conform to ANSI B107.7 specifications.,All Proto sockets are made from special alloy steel that permits a high strength, thin wall design, for use on fasteners that are extremely close to obstructions.,Four internal detents on the drive end provide positive engagement to the drive tool.