The OSPW System for Shimano is compatible with Ultegra/Dura Ace (6800/7800/7900/7970/9000/9070), 10s and 11s, electric and mechanical groupsets. Developed and designed entirely by CeramicSpeed, the Oversized Pulley Wheel System for Shimano is advanced for the optimization of bike performance, where the watt savings start at 2.4 watts. Everything from bearings to the cage is made from the highest quality materials. The 17-tooth aluminium pulley wheels are fitted with standard or coated CeramicSpeed bearings, which reduce friction to the minimum. The overall power savings of the OSPW System for Shimano reach 60% or more in some cases. The OSPW System has a lifetime that lasts 3-5 times longer than the commonly used standard pulleys on the market.