14 Piece 1/2" Drive Manual Impact Driver Set (Hammer-Driven) How they work: You hit the back with a hammer. Internal cams turn the hammer strike into sudden rotational force. Best use: Removing rusted, stuck, or stripped brake rotor screws, motorcycle engine covers, and old machinery fasteners. Features: Heavyweight, drop-forged, knurled impact chrome-vanadium steel body resists impacts, prevents bouncing. Reversible train for tightening or loosing fasteners. Impact CR-V Steel 12" Drive Socket and 5/8" hex shaft bits Can be used with any impact duty 1/2" drive sockets. Contents: 1/2" Drive Reversible Impact Driver 1/2" Drive Removable Impact Socket Flat head bits: 3/16", 1/4", 9/32", 5/16", and 3/8" Phillips head bits: #1, #2, #3, and #4 Hex bits: 3/16", 1/4", 9/32", and 5/16" Case Dimensions:7.45" x 2.25" x 1.5" CTT-CSDID14