Armstrong 15-361 3/8-Inch Drive 6 Point Socket Set with Plastic Socket Rail, 13-Piece Thin wall design with precise fastener end dimensions meet industrial specifications Radius corner design provides 15-20-Percent more torque which extends fastener life and reduces slippage Large EYE-D size markings ease identification and provide SAE/Metric differentiation Proudly manufactured in the USA Lifetime Warranty