The DT Swiss Star Ratchet Kit includes two 54t ratchet wheels to replace the factory-stock 18t ratchet wheels. The pitch of the teeth are decreased from 20° to only 6.6°. What this equates to is faster and more stable engagement on any DT Swiss 190 Ceramic, 240S, 440 and 350 freehubs. They will also upgrade pre-built DT Swiss RR, XR and FR series wheelsets. Installation is a breeze and is a quick way of making a great hub even better.