🚴 IMPROVES PEDALING SPEED BY REDUCING FRICTION: Jockey Wheel 15T/17T with hibrid ceramic inner bearing with steel rings compatible with Shimano Jockey Wheels . Minimal friction that significantly improves performance thanks to a much smoother transmission and maximum durability due to the steel rings 🚴 ULTRALIGHT AND RESISTANT: Aluminium 7075 CNC machined ensures maximum strength and durability with the least weight (Ultralight 14g) and a perfect finish. The MTB jockey wheels are anodized in 5 different colors (black, red, blue, gold and silver) to prevent rust and corrosion 🚴 COMPATIBILITY: Compatible with Jockey Wheel SHIMANO and SRAM: shimano jockey wheels 11 speed, shimano jockey wheels 9 speed, sram eagle pulley, derailleur pulley 11 speed, shimano deore, shimano XT, etc... 🚴 INSTALLATION: The rear derailleur pulley wheel is very easy to install with an allen key by simply removing the screw that holds the piece to the derailleur. Adapt the pulley to the size of the screw (4, 5 or 6 mm) with the included accessories. Make sure the screw is 11,5mm or longer to ensure compatibility. Do not overtighten because it would increase friction with the pulley, reducing its performance. 🚴 100% GUARANTEE: Customer satisfaction is our priority. If you have any questions, problems or you are not satisfied with the product, please email us and we will help you to solve it as soon as possible IMPALAPRO Bike Oversized Ceramic Derailleur Pulley Wheel 15T/17T AL7075 compatible with Shimano jockey wheels and rear derailleur pulley Sram