The Jockey Wheels XD15 Ceramic - SRAM Eagle AXS 12sp by Enduro Bearings are the ultimate upgrade pulleys for your bike. These precision machined Delrin Derailleur pulleys feature XD-15 Ceramic-Hybrid, radial bearings that enhance shifting performance and longevity. Designed and manufactured for performance, these pulleys have CN bearings in the upper pulley to maximize shifting accuracy and C4 bearings in the lower pulley to allow for chain-line movement. Made from 500 AF Delrin pulley material, these pulleys are highly durable, rigid, and very smooth. The material is resistant to corrosion, moisture, caustic chemicals, and UV, making it last forever. Compared to other pulley materials like aluminium or titanium, the 500 AF Delrin with Teflon offers significantly less drag. These pulleys feature Enduro Bearings' exclusive XD-15 Ceramic-Hybrid bearings, which combine corrosion-proof, cryogenically treated nitrogen steel races with Silicon Nitride Grade 3 ceramic balls. This high-performance bearing setup provides improved performance and longevity. The deep-groove design raceways allow for maximum-sized Grade 3 Silicon Nitride ceramic balls for increased contact area.The pulleys come with 90% fill Kluber NBU52 grease, which only runs better and smoother with time. It is highly resistant to being washed out and sticks to the balls, continually being pulled back into the ball path where it is needed. These jockey wheels are designed as an upgrade for most 11-speed Campagnolo derailleurs. Enduro Derailleur Pulleys are available in various configurations and performance levels, including Ceramic-Hybrid, Black-Oxide treated Zero Ceramic, and XD-15 Ceramic-Hybrid. All of these are proudly precision manufactured in the USA. Compatibility: SRAM Eagle AXS 12spBearing Grade: XD15 CeramicEnduro Part Number: BKCJ-0506