3-Piece Deep Combination Impact Socket set is great for a variety of needs Feature DirectTorque technology to prevent rounding of fasteners Heat treated CR-440 steel with a black oxide coating Visible laser etched markings O-Ring and retaining pin compatible Includes: 3/8” Drive 6pt deep impact sockets Metric: 12 13 14 15 16 17 18 19 20 21 SAE: 3/8 7/16 1/2 9/16 5/8 11/16 3/4 13/16 7/8 1 3/8” Drive 6pt Impact Extension 3” 3/8” Drive Quick Release ratchet 3/8” Drive Drill adapter