Forging with industrial-grade steel, integral heat treatment, higher hardness and impact resistance. Hexagon screw connection and concave groove design to prevent falling off. Fine polishing electroplating anti- knurling surface fine polishing treatment, bright chrome electroplating, knurling design to increase friction. supporting storage plastic boxes are practical and , and easy storage tools are not messy and more convenient to carry. Name: -V -V steel sleeve Short version of 10 pieces 3/8 inch: 8/10/12/13/14/15/16/17/19 /22mm. Colour:silver Material:steel Package Contents: 10 x 3/8 short hexagonal sleeve Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.