Campagnolo 11-speed rear derailleurs work best with our pulleys, which represent a clear improvement over the original ones. Ours reduce drag friction and increase bearing life. Less friction means more power transferred to the rear wheel. There are three options. The first is CNC-machined aluminum pulleys with our standard CeramicSpeed balls installed in our hardened steel cages. These are our Standard Bearings. These test better than anything else on the market. Second, CNC-machined titanium pulleys with our Standard Bearings. Third, CNC-machined titanium pulleys with our ceramic balls installed in coated hardened steel cages. Our Coated Bearings. These are compatible with all Campagnolo 11-speed derailleurs, both mechanical and electronic. In the package: 2 x 11-tooth pulleys 4 x spacers UFO TECH BEARING OIL Dropper bottle, 15 ml Decal