The oxford alarm d duo max u lock with cable is a high level sold secure silver rated alarm integrated d lock as if having a silver rated sold secure lock wasnt enough oxford have pushed the boat out and encorporated a 120db alarm which will scare any thief constructred from a super tough hardened steel the lock is burly and can withstand a beating the weatherproof alarm is powered by a long life lithium battery and has an output of 120 db which is at a similar level to the siren on a fi