Suitable for Red eTap AXS™ rear derailleurs and intended for road use, this kit allows you to upgrade your derailleur by installing a Ceramic 2-Kit roller on your Sram Red AXS 12-speed rear derailleur. The X-Sync design of the pulleys from SRAM, helps to maintain the chain and reduces friction for a smoother shifting. The ceramic bearings offer a very low coefficient of friction and excellent power transfer. This increases the service life of the bearings Characteristics : Tooth size: 12Speeds: 12 speedsBearing : ceramicSold in pairs.Sold with a syringe of specific grease for ceramic bearings.Weight : 88gReference : 00.7518.127.000Compatible only with Red eTap AXS 12 speed derailleurs (Road).Note: The two rollers have a different design. It is therefore important to mount them in the correct order. They are numbered 1 & 2.