Stanley J07567 Proto 3/4-inch Drive Impact Extension 7-inch Use extensions to gain access to fasteners in locations that would otherwise be difficult to reach. Male square is oriented in-line with female squares for use with fixed head torque wrenches. Full chamfer at drive opening (when applicable) for easy engagement with drive tools. Drive end chamfer and four detents help provide quick positive engagement with drive tool on any of the socket drive walls. Features two thru holes and a groove to accept a Proto retaining ring or pin or O-ring to help secure extension to the drive tool anvil.