[ EXTRA STRONG ] The socket is made from chrome vanadium steel with an S2 steel bit for strength and flexibility. [ INCREASED GRIP ] Satin finish for a better grip when handling the socket - perfect for oily environments. [ FOR HEX FASTENINGS ] Designed for use with hexagon hole fastenings. Use with in-hex screws or grub screws. [ INSTANT IDENTIFICATION ] The socket features roll stamped markings to ensure permanent and instant socket identification. [ SECURE DRIVE ] Ball bearing recess on the female end to grip a ratchet or extension bar securely.