ceramicspeed-shimano-11-speed-pulley-wheels-coated-bearings-silver
ceramicspeed-shimano-11-speed-pulley-wheels-coated-bearings-silver, CeramicSpeed pulley wheels reduce friction, last 3-5 time longer than stock high-end pulleys, and are designed to work with less drag.Premium Grade 3 Silicon Nitride Ceramic ballsHand built in Denmark