Derailleur / Chain tensioner jockey wheels from Hope (for Shimano and SRAM derailleurs), and Brompton
Pair of Hope 12 tooth Jockey Wheels - Bronze
Hope 14 / 12T Jockey Wheels (pair) - Bronze
Shimano Ultegra RD-6800/6870 tension and guide pulley set
Hope 13T Jockey Wheels (pair) - Bronze
Sram NX/SX Eagle Rear Derailleur Pulley Kit - Includes 12T Upper And 14T Lower Pulley, with Bushings, 13mm And 14mm Pulley Bolts