This is achieved through the synergy of superior chrome-vanadium steel and a robust, thickened inner wall design. Our tool set are all made from quality chrome vanadium steel alloy, and its mirror chrome plated finish perfectly achieved outstanding strength and wear resistant. tool kit: Our small socket set included 21pcs bit sockets: SL4,5.5,7, PH1,2,3, PZ1,2,3, Hex 3,4,5,6,7,8 T10,15,20,25,30,40 and 13pcs 1/4 Dr metric sockets(4-14mm): 4, 4.5, 5, 5.5, 6, 7, 8, 9, 10, 11, 12, 13, 14 mm 1/4 quick ratchet handle. Multi extension bars: This ratchet wrenches set included multi extension bars is suitable for various scenarios: 1/4""dr universal joint, 1/4""dr x 2"" extension bar, 1/4""dr x 4"" extension bar, 1/4""dr x 6"" flexible extension, 1/4""dr sliding t-bar, 1/4""dr sliding t-bar, 6"" spinner handle and 1pc-bit adapter. This socket wrench set is for home improvement, carpentry tools, construction, auto repair, woodwork, and other Diy projects. Weight: 2.64 pounds.