Ergonomically-shaped for comfort. Includes all three rollers - Blue for cold, Red medium/universal, and Yellow for warm conditions. Use it AFTER waxing and be sure to brush after applying the structure. Subsequent waxing will remove most of the structure, leaving it ready for the next structure choice. Rollers press temporary structure into base rather than cutting permant structure. We have used it alone and in combination with other rillers with good results.