The RS Razor Wheel is the world's most advanced Pinewood Derby Car Racing Wheel to date. With features like the Patent-Pending Anti-Friction Inner Strip, A-Cad engineered design for perfect balance and machined from Delrin on a CNC for exacting tolerance, the Derby-Worx Pro RS Wheel is ready to run. These white wheels can be colored to your choice with clothing dye (Picture shown is of black wheeels). Just add your choice of lubricant. Check your local rules to see what wheels are permitted.