Milwaukee Impact Sockets Deep 3/8" Drive Shockwave Impact DutySHOCKWAVE™ IMPACT DUTY steel (Chrome-Molybdenum) is high quality alloy steel which provides ultimate strength and durabilityBest fitting thanks to 6 gripping pointsRecessed corners allow torque to be transferred across the flats of the socket rather than producing stress on the points or cornersThin wall construction provides access to tight spacesDeep wall construction provides clearance for protruding boltsLaser etched size markings for easy identification and won't wear off