Bicycle Rear Derailleur Pulley Wheel 12T For-SRAM for XX1 XO1 for X1 for GX NX Apex、 for Rival、 for Force、RED 11Speed. Model: 12T. Narrow wide Wheel. Material: Plastic. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness.
eBay