CeramicSpeed Oversized Pulley Wheel SystemThe coated bearings in the CeramicSpeed Oversized Pulley Wheel System give you extended durability and longevity of the product. It has been developed for performance optimisation, and the watt savings start at 2.4 watts. The cage is made from carbon fibre and reinforced PA while the 17-tooth pulley wheels are made from aluminium and mounted with high quality CeramicSpeed coated bearings.The revolutionary OSPW System is mounted with CeramicSpeed coated bearings, which means it has undergone a special coating treatment to provide even more protection and lower friction. A very thin protective coating is applied to the bearing races, which further increase the resistance to corrosion or damage from foreign objects.The OSPW has been tested and confirmed to be the worlds fastest pulley wheel system, therefore enhancing your performance with free speed, which gives you a more efficient drivetrain. Like all other products delivered by CeramicSpeed, this product has undergone a thorough testing program and is used by professional triathletes Tim Don and Tyler Butterfield. Features:Material: Carbon/PA Cage, Aluminium Pulley Wheels Shimano Compatible 10 or 11-speed Weight: 57gMaintenanceIts important that you properly lubricate your bearings in order to ensure optimal performance and maximum longevity. Add oil to the outside of the bearing seal, so that oil can penetrate the bearing. Do this when you lubricate your chain, or if you have washed your bike or have been riding in wet or muddy conditions. Buy CeramicSpeed Components from Chain Reaction Cycles, the Worlds Largest Online Bike Store.