Armstrong 38-312 12mm, 12 Point, 3/8-Inch Drive Metric Deep Socket Grips the fastener across a broader contact area allowing for 15% to 20% greater torque and less chance of fastener rounding Chamfered opening provides faster and easier socket fit over the fastener Thinwall construction means better access to fasteners in limited areas Precision cold formed of special steel for exact, consistent dimensions and greater strength Proudly made in the USA with a lifetime warranty