1、Aluminum Alloy: 7075 aluminum alloy guide plate, high strength without breaking, strengthened rocker arm support structure safety, stable and fast speed change. 2、Ceramic Bearing Guide: The 16 tooth bearing guide wheel can more precisely fit the chain, reduce the lateral virtual position, shorten the speed change response time, and improve the speed change efficiency. 3、Fast and Smooth: The guide wheels are made of aluminum alloy, upgraded to ceramic bearings, frictional power consumption is reduced, climbing is labor saving, and the cadence is effectively improved. 4、Scope of Application: Road bike rear derailleur guide wheel is suitable for 6800/6870/6770/9000/9070, for ultegra, for DURA ACE, can effectively improve the performance of your bicycle. 5、Easy Installation: Easy to install and remove, convenient to use, exquisite workmanship, beautiful appearance design, providing users a good using experience. Item Type: Road Bike Rear Derailleur Guide Wheel Product Material: Aluminum Alloy Weight: Approx. 125g / 4.4oz Product Model: 6800 Series Models (Model 8800RD) Application: for 6800/6870/6770/9000/9070 for ultegra, for DURA ACE 1 x Bicycle Rear Derailleur Guide Wheel Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.