This is a REDS Racing 13 Tooth 1/8 Off-Road Vented Clutch Durabell. This clutch bell is used with the optional REDS Engines 4-shoe and 3-shoe clutch systems. The REDS Racing Durabell clutch bell is made from high quality steel and the special coating allows the teeth to last longer than any other standard clutch bell on the market. A special vented design also guarantees lower temperatures and more consistent shoe engagement for a longer life of both bell and clutch shoes. The Durabell is available in 13 and 14 teeth version only and it is suitable for Kyosho, Mugen, JQ, Associated, Hot Bodies, Serpent and XRAY. Specifications: Inner Diameter: 26.6mm Bearings Size: 5x10x4mm