9 Pc Shallow Impact Sockets Set, 1/2" Drive, Metric. 9 pc Shallow Impact Sockets Set, 1/2" Drive, Metric. Impact sockets are drop forged heat treated steel. Heat Treated Oil-Quenched, Black Oxide Finished Set includes: 11mm, 12mm, 13mm, 14mm, 17mm, 19mm, 21mm, 22mm. Includes socket holder or storage rack.