Off-corner loading design reduces fastener rounding; Chamfered opening quickly guides fasteners into socket; Serration depth inside the socket is as deep as the fastener hold it in the correct position; Hard stamped size markings; Double line (SAE) and knurled (metric) ring help easily identify standard and metric sockets; Bright, full polish chrome finish easily wipes clean and resists corrosion; Includes socket rail for storage and organization; Meets or exceeds ASME specifications