A disc lock is a portable security device for motorcycles and scooters. Disc-locks use the holes in a motorcycle's or scooter's brake disc. A locking pin passes through the hole in the brake disc and locks to the other side of the lock, using either a pushdown-and-click locking mechanism or a more robust double-locking mechanism. When in place, the disc-lock discourages theft by blocking the vehicle from being moved in either forward or reverse direction.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/3/3f/Motorcycle_Disc-lock.jpg/220px-Motorcycle_Disc-lock.jpg)