IMPROVE THE BACKPEDAL PERFORMANCE OF YOUR 11 SPEED SHIMANO CASSETTE WITHOUT LOSING RANGE. Note: All OneUp Components 50T and 45T expander sprockets kits already include our 18T sprocket. The OneUp 18T sprocket and spacer kit replaces the 17T and 19T sprockets within a stock 11 speed Shimano cassette and spaces the cassette out by 4mm which greatly reduces back-pedal chain dropping issues. The 18T kit removes one gear from your cassette without changing the stock range and is only compatible with 11-speed components. Simply use your low limit to remove one click from your rear shifter. SPEC ~ Sprocket material: Chrome plated hardened steel ~ Sprocket weight: 24g (18T), ~ Compatibility: For XT/XTR M8000/M9000 11-40T, XT/SLX M8000/M7000 11-42 cassettes. Also compatible with the OneUp 10T cluster. Cassette progression: 11-40, 11-13-15-18-21-24-27-31-35-40 11-42, 11-13-15-18-21-24-28-32-37-42 INSTRUCTIONS ~ Mount the OneUp green spacer first and reinstall all sprockets except the stock 17T and 19T sprockets (these are replaced with our 18T and aluminum spacer). ~ Adjust the low limit screw to eliminate the final click on your shifter Please visit our website at http://www.ecomtb.com.my OR https://shopee.com.my/eco_mtb ** There is 1-3cm errors due to manual measurement. Please kindly understand. ** Actual product colour may slightly vary due to photographic lighting sources or your monitor settings. ** WE DO NOT DO COD ** ONLINE ONLY ** We support original products only. ** PRICE INDICATED IS ALREADY BEST PRICE, EXCLUDE COURIER