The quality of the material is low for this kind of nuts but it is a cheap product so don't expect too high quality. The black color comes from the coating so I expect it to peel off over time which isn't a big deal to me. The car I bought this for has 4 lug nuts per wheel so I have 1 spare lug nut for each wheel which is great. I have another set of quality forged nuts for my sports car. In comparison, the material of the nut appears light. I would not use this for racing/heavy duty. I used this product on a sunroof car for daily driving.