All 21-piece socket wrench inserts are made of Cr-V steel and are matt chrome-plated.
Suitable for metric sizes: 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 24 mm, 27 mm, 30 mm, 32 mm, 34 mm, 36 mm.
The insert are simply put on the torque wrench or impact wrench.