Radar Riva Wheels are an inexpensive indoor wheel with a durometer hardness of 96A. These are great for coated surfaces like rink floors or polished concrete. These wheels are mainly used by recreational artistic skaters, rhythm and session skating, artistic and dance skaters, or jam skating. Check them out if you are looking for a hard wheel for indoor surfaces. These wheels are sold in 4 packs. Sized at 32mm X 57mm.