U-lock. Lock type: U-lock. Locking system: Key. Length: 245 mm. With M-Wave's U-locks, you make life difficult for potential thieves. The very robust B 245 lock, with a shackle thickness of 14 mm, is one of our flagship products. This product can be easily opened or closed with one of the computer-designed keys, and the keyhole is located behind a dust cover. The external dimensions are 197 x 245 mm, and the internal dimensions are 105 x 205 mm. Simply mount the included holder on your bike, secure the lock to it, and you're ready to go.