Mammoth Gremlin Alarm Motorcycle Disc Lock 6mm The Mammoth gremlin alarm motorcycle disc lock 6mm is a super-strong motorcycle and scooter alarm disc lock with a 110dB loud alarm and 6mm hardened steel pin. Simply attached this to your front disc brake, suitable for 6mm size pins. Best paired with a reminder cable, so you don't forget to unlock your disc lock before you ride off. Motorcycle Alarm Disc Lock Features: 110dB motion-activated alarm. 6mm Hardened steel pin. Easy to use. Comes with 2 keys. Small and lightweight. Easy to store away. Zinc alloy body Replacement key service.