Armstrong 12-416 1/2-Inch Drive 8 Point Standard Socket, 1/2-Inch Made in the USA - quality and availability EYE-D markings optimize size visibility, also providing SAE / metric differentiation Unique socket retention method, cold form ball recess, provides consistent secure retention of the socket to the drive tool eliminating the possibility of either a loose fit or tight fit Socket wall dimensions are optimized to provide strength while retaining access to restricted fasteners Manufactured from high alloy steel using the most up-to-date manufacturing process and heat treat for greater strength and durability