Amazon.com : BOLANY Bike 10 Speed Cassette 11-25T/32T/36T/40T/42T/46T/50T Fit for MTB Bike, Road Bicycle, Lightweight Freewheel Super Light, Compatible with Shimano SRAM Sunrace (Black+Silver 11-40T) : Sports & Outdoors
Shimano Cn-4601 Mountain Bike 10 Speed Chain/Bicycle Accessories - China Accessories, Chain | Made-in-China.com