BKCJ-0331 - 11 tooth, XD-15 Ceramic Hybrid Bearing, Machined Delrin Derailleur Pulleys for 11 speed Campagnolo Derailleurs (5mm bolt hole)The Jockey Wheels XD15 Ceramic - Campagnolo 11sp from Enduro Bearings are the ultimate upgrade pulleys for your Campagnolo 11 speed derailleur. These pulleys are guaranteed to last forever against corrosion and offer enhanced shifting performance and longevity.Made from precision machined Delrin material, these pulleys feature XD-15 Ceramic-Hybrid, radial bearings that provide smooth and accurate shifting. The upper pulley has CN bearings for precise shifting accuracy, while the lower pulley has C4 bearings that allow for chain-line movement.The 500 AF Delrin material used in these pulleys is highly durable, rigid, and offers natural lubricity. It has a high resistance to moisture, caustic chemicals, and UV, making it perfect for use on your bike. The Teflon-infused material also reduces friction when in contact with the chain, resulting in improved performance.These pulleys feature Enduro Bearings' exclusive XD-15 Ceramic-Hybrid bearings. These bearings are corrosion-proof and have been cryogenically treated with nitrogen steel races and Grade 3 ceramic balls. The deep-groove design allows for maximum-sized ceramic balls, which improve performance and longevity. The Kluber NBU52 grease used in these bearings provides optimal lubrication and is highly resistant to being washed out.The XD-15 Ceramic-Hybrid pulleys are specifically designed as an upgrade for most 11 speed Campagnolo derailleurs. They are part of a range of Enduro Derailleur Pulleys available in different configurations and performance levels. All Enduro Derailleur Pulleys are proudly manufactured in the USA.Compatibility: Campagnolo 11spBearing Grade: XD15 CeramicEnduro Part Number: BKCJ-0331