High technique requirements O-Ring Roller Chain:35,40,50,60,80,100,06B,08B, ... 10B,12B,16B The service life of O-Ring Chain is greatly depended on the wearing between the ... pin-shaftand the sleeve. The "O" ring will greatly reduce the wearing and thus prolongthe service life ... It is most suitable for high-speedrunning.Our brand O-ring chain be recommend the no. 1 in Chinese chain ...