Artistic roller skaters skate on quad skates or inline skates (for the inline free skating discipline). Skates consist of four essential parts: boots, plates, wheels, and bearings. Skaters may sometimes use jump bars on their plates for added stability. Free skaters (both quad and inline) have a toe stop on their plates. While plates are usually long lasting and durable, boots, wheels, and toe stops need to be replaced as they wear down with use.