All the results of the simulations and the experimentations indicated that the ceramic ball bearings' performances are very good, especially in the low load and high-speed environment.<br> Specifications:<br> specification<br> Size:11T<br> Structure: Ceramic bearing<br> Material: aluminum alloy 7075<br> Color: Black Red Blue Silver Gold<br> Weight: about 7.8g<br> Fit for 4/5/6 MM roller screw axis<br> Apply for most of rear derailleur on the market<br> Package Included:<br> Jockey Wheel*1<br> Notes:<br> Please check the detail size/model information before purchasing.<br> Due to the different monitor and light effect , the actual color of the item might be slightly<br> different from the color showed on the pictures . Thanks for your understanding.<br> Please allow 1-2 cmmeasuring deviation due to manual measurement.<br> Chat with us should you need any assistance.<br> Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-DIMEANI official store