The SW-7 is electroless nickel plated for years of service. The precision sized SW-7 fits the three most popular spoke nipple sizes on the market. The three sizes of the SW-7 are marked "0", "1", and "2". These are equal in sizing to the SW-0 (black), SW-1 (green) and SW-2 (red) respectively. The "0" is sized for 3.22mm (0.127") nipples and fits Wheelsmith, Marwi and DT, Edco as well as other brands of nipples. The "1" is 3.3mm, and the "2" is for 3.45mm nipple sizing (common on many Asian built bicycles). Please note that the spoke gauge or size does not dictate the nipple size.