AFAM : AFAM Chain kit 520XHR2 15/42 Super-Reinforced - Ultra-light Hard anodized rear sprocket €198.97
AFAM 48011429 : AFAM Chain Kit 520MR2 9/44 Standard - Ultra-Light Hard Anodized Rear Sprocket €103.31
D.I.D : DID/JT Chain Kit 520ERT3 12/51 Super-Reinforced - Ultra-Light Self-Cleaning Rear Sprocket €102.20