Square Sockets, 28992, 1/2 in Drive, 9/16 in, 4 PointsApex Impact sockets from Apex have hex tolerances that are on average 48% tighter than DIN and 35% tighter than ANSI requirementsApex impact sockets provide an exact, sure fit every timeImpact sockets from Apex Fastener Tools provide the tightest tolerances for