Set of quality made urethane 78A Durometer wheels with good grip good for indoor or outdoor Roller Skating surfaces. Colored lights light up when the wheels spin - no batteries or other power source is required - they work by the spinning action of the wheels alone! They come pre-installed with Abec 7 8mm bearings! Choose INSTOCK from Available colors and Wheel sizes in the Pull-down Menu! Sold in sets of 8 Ready to Roll!