... High technique requirements O-Ring Roller Chain:35,40,50,60,80,100,06B,08B,10B,12B ... service life by 5 times. It is especially suitable for the adverse environmentssuch as the one bearing water, ... mud or dust. It is most suitable for high-speedrunning.Our brand O-ring chain be recommend ... the no. 1 in Chinese chain association, berecommend to worldwide.1) Model: 35,40,50,60,80,100,06B ...