This is a quality product, just make sure you order the right ones. The ones I received had to have the stock 6 x 5.5 steel truck wheels fitted to the Nissan Frontier. They feel nice and firm, I would imagine they're polycarbonate, they're hard like a thermoset rather than soft and don't warp. However. This is not a product malfunction or defect, you just need to know what you are doing. These things are literal, so if you have center-capped wheels like I do, they're useless to you. I have 108โฆ