1/2" Drive 6 Point Standard Metric Socket 13mm. Off-Corner Loading Design Reduces Fastener Rounding. Chamfered Opening to Guide Fastener Into Socket. Large Hard-Stamped Size Identification. Double Line (SAE) and Knurled (Metric) Ring to Easily Identify Standard vs. Metric Sockets. Full Polish Chrome Finish Cleans Easily and Resists Corrosion.