Oxford Products all new XA14 brake disc lock with built-in 110dB motion alarm A super strong disc lock with 14mm dead-bolt locking steel T pin. The lock can be installed on the brake disc (or transported) in alarmed or non-alarmed mode. The 110dB alarm module is replaceable in case of defect and the integrated Lithium Polymer battery is USB (micro) rechargeable. The rear of the lock features a handy eyelet to attach the included reminder cord. Alpha XA14 carries the UK's prestigious Sold Secure testing label Forged stainless steel construction14mm double locking T pin110dB alarm USB Rechargeable lithium battery High pick resistant 5 disc cylinder Can be used with or without alarm Reminder cable included Operation Slide the lock onto the front brake disc with key inserted into the lock. Look for an opening large enough to pass the pin through. Push the cylinder in with the key until the bottom of the T-pin is inserted in the bottom part of the lock. Turn key counter-clock to close. To install the lock with alarm: Push the cylinder only ones when closing the lock. You hear one beep indicating the alarm is armed. To install the lock without alarm, push the cylinder in twice before locking. You hear 2 beeps indicating the alarm is disarmed. This is also how you transport the lock. Dimensions: Pin size: 14mm - 0. 55inMaximum disc clearance: 50mm - 2in(you need an opening larger than 0. 55 inch and not further away from the edge of the brake disc to edge of the hole than 2 inch)