Ingco Screwdriver Set is a high-quality tool that will allow you to work for a long time using. It is made from chromium-vanadium steel (white nickel plated). The handle is also made from Hard plastic. Set includes 21 piece size 6.35x25 mm: SL4, SL5, SL6, PH1, PH2, PH2, PH2, PH3, PZ1, PZ2, PZ3, T10, T15, T20, T25, T30, T40, H3, H4 , H5, H6 Precision Bits. 20 piece 4x28 mm: SL1.5, SL2, SL2.5, SL3, PH000, PH00, PH0, PH1, T6, T7, T8, T9, T10, T15, T20, H1.5, H2 .0, H2.5, H3.0, H4.0. Bit Adapter size 4-6mm (25mm): 1 piece Sockets 1/4-inch x20.5 mm 9 pieces: 4, 5, 6, 7, 8, 9, 10, 11, 12mm Bit holder 4x60 mm: 1 piece Bit holder 6.35x50 mm: 1 piece Unique design ratchet handle: 1 piece Unique design handle: 1 piece plastic case.