Improving the issue of original parts that can’t rotate freely when dirt or water gets inside. It can reduce the friction and resistance between chain and rear derailleur.
That means the chain can work smoother and unhindered, also improve the performance of variation in speed, uphill especially. And its narrow-wide tooth design can throw out chain drop with the prefect chain mesh fit.
P.S. Please make sure the marks facing outward.
• Material: Aluminum 14T & 16T Pulley
• Weight: 28g
• Compatible System: SHIMANO 12S
• Color Available: Black / Gold / Purple