Have you wanted to try upgrading your pulley system to the OSPW(Over Sized Pulley Wheel) system but only ever we he expensive carbon options? Give this a try, alloy cage and bearings, 11t 16t
Model Name : SHA1
Cage : Al
Pulley : Al
Bearing : Stainless steel ball
Teeth : 11T + 16T
Compatibility : Type A - Shimano Dura Ace, Ultegra (6700/6780/6800/6870/7800/7900/7970/9000/9070 10s/11s)
Type B - Shimano 105(old) (5600/5700/5800 10s/11s)