METRIC, ¼” DRIVE, SURFACE DRIVE, DEEP, CHROME HAND SOCKET SET.  The Ko-ken RS2310M/12 is a 12-piece 1/4" Sq. Dr. Surface Drive Deep Socket Set designed for enhanced torque transfer and reduced nut wear. Featuring a Surface Drive design, these sockets make contact with the flat sides of nuts, distributing force more eve 12 Piece 1/4 Sq. Dr. Surface Drive Deep Metric Socket Set