Dual Drive - 10 Triple Square Bit Made from S2 Tool Steel with proprietary heat treat for superior strength and durability .Mayhew's socket bits have a precision tip profile for positive and precise fastener engagement . Sockets feature a chrome plating for added strength and wear resistance. Precision tip profile manufactured for positive and precise fastener engagement. Titanium Nitride coating for added strength and wear resistance. Unique dual drive design allows for bit to be driven by a ratchet, socket spinner or open end wrench 16147