RollerBoys (jockey Wheels) equipped with low friction ceramic bearings for ultra-smooth glide and exceptional durability.
 
Top Features:
Lubricated with special ceramic light oil for extra smoothness
Composite material provided by EMS Swiss, with 40% glass-fibre
Complete set of bushings for different shifting systems included
Ceramic bearings
11T. Compatible with Shimano 9, 10 and 11-speed / Mega Range and Campagnolo 11 speed.