Chrome vanadium steel with polished heads on a plastic hanging rack. This set includes 8 offset ring spanners in metric sizes ranging from 6mm to 22mm. The sizes included are: 6 x 7mm, 8 x 9mm, 10 x 11mm, 12 x 13mm, 14 x 15mm, 16 x 17mm, 18 x 19mm, and 20 x 22mm. The spanners are nickel chrome plated for durability.