The SL Carbon cassette spacers give you the perfect adjustment to convert your 5-9 speed cassette hub to single speed. By replacing un-used cassette sprockets with a set of SL Carbon spacers it is possible to save hundreds of grams from the weight of your bike! As a kit of five individual spacers of varying sizes, a combination can be made that fits perfectly with all most any single or multiple sprocket sets. Made from 100% carbon fibre, the whole kit weighs just 10g and with the bold Trialtech logos and raw carbon weave they add a stylish look to any cassette hub.