Rollerbones Day of the Dead 92A Speed/Derby Wheels with a Nylon Core (Set of 4) An excellent wheel at an excellent price point; Preferred wheel for most disciplines, speed, jam, recreational & roller derby Our unique urethane & high level of quality control make our wheels the best on the planet Great for indoor & outdoor skating Roller bones Day of the Dead wheels have an excellent combination of grip and roll and work on a variety of surfaces