Meet OTTO, a bike tuning system sidekick that guarantees smooth derailleur shifting. Just when you think you’ve fixed your rear derailleur, the non-stop clicking and miss-shifting continues, this time in another gear. The OTTO is a simplified Tuning System that guides rear derailleur maintenance for those with little previous bike tuning knowledge. It’s as simple as aligning the OTTO to the OTTO app via your phone’s camera, mount the OTTO to your drivetrain, then sync again and wait for your index score. From your OTTO score you’ll know the exact direction to turn your barrel adjuster. The OTTO system will also give you angle and twist scores, informing you if the derailleur is bent and completely miss-aligned. This handy tool is compatible with Shimano or SRAM 10/11 and 9 speeds, regardless if you’re riding downhill, road or x-country.