The Oversized Pulley Wheel System for Shimano Dura Ace 9200 and Ultegra 8100 with integrated stop tower for simple installation and durability. The CeramicSpeed Oversized Pulley Wheels System has been proven to be the fastest pulley system in the world. CeramicSpeed OSPW Systems are an industry leading product, chosen by World Champions and top athletes around the world. This OSPW System has handbuilt CeramicSpeed Bearings installed in each pulley and comes with a 4 year warranty as standard and a lifetime warranty when choosing coated or SLT bearings. Featuring a 13-tooth upper pulley wheel and a 19-tooth lower pulley wheel to provide absolute optimisation of the rear derailleur. The upper and lower oversized aluminium pulley wheels come fitted with either standard or coated CeramicSpeed Bearings. Please note while there are visual similarities in the 9100 Series OSPW and 9200 Series OSPW, the spring tension settings, rotation stop tower placement, and mounting pin depth are slightly repositioned and as such the systems are not cross compatible. The 12spd Shimano R-7150 105 is not supported at this time. For 8100 derailleurs, the cage uses the factory derailleur body washer. 9200 derailleurs will require the new included derailleur body washer.