The Lisle Corporation 11-pt Truck Brake Caliper Socket, No. 29120, is designed for truck air disc brake caliper adjustments. The socket works on Bendix ADB 22X, ADB 225, SN6, SN7, SK7 air disc brake calipers. The socket is used when replacing the original shear or break-away adapter during caliper adjustment mechanism service. The socket measure 26mm long for clearance in tight spaces. For use with a 3/8" square drive.