Features: 6-point Design --- 6-point socket design enlarges contact surface between sockets and fasteners, locks force more firmly, reduces wear and prevents rounding off at corners. Variouse Size --- Set includes 7 common metric sizes for impact sockets; 4mm5mm6mm7mm8mm10mm12mm. Superior Quality --- Highly Cr-Mo steek with durable black oxide coating finish is corrosion resistant to eliminate chance of rust for a long lasting tool life. Customized Storage Case --- Designated slots in the case keep every piece in place and sockets don't fall off and slip. Sizes are also stamped beside each slot for identification. Compatible With --- For use with 3/8" manual wrenches, pneumatic electric wrenches,and Remove inner torx screw. Specifications: Material: CR0 Steel Size: H4/4mmH5/5mmH6/6mmH7/7mmH8/8mmH10/10mmH12/12mm Package Weight: 440g/15.5oz Package Size: 15*9*5cm/5.9*3.5*2.0in Package List: 7 * Impact Socket 1 * Carry Box