Made of CrMo steel. 3/8” wrench-operated (3/8” drive included). Dimensions included: 4-point external 8-11-12-13-14- 5/16”-3/8”-1/2”. 6-point external 8-9-10-12-14-17-5/16”-3/8”-1/2”. 3-point external 10 mm. 12-tooth XZN16 VW. 4-point internal 10 mm.