With the One Key System, you can use the same key for all locks! The Thule One Key System makes your life easier when you mount lockable accessories on your roof rack. Just replace the lock cylinders of both the roof rack and the accessories (roof box, bike rack, etc.) and you can use a single key for all the locks! Depending on how many accessories you have, you can choose the Thule One Key System in 4, 6, 8 or 12 barrel versions.