Alarm will only sound when lock is being attacked, cut or a strong impact (caused by dropping or banging against another object). The alarm resets automatically This high security design is rainproof, rust proof & weatherproof. It is ideal for garden sheds and houses, garages, caravans, bicycles, gates etc. Simple to operate and easy to install. - Heavy-duty, waterproof and very good quality. - Corrosion resistant. Keep your bike, garage door, garden shed, side gate, tool box or locker, or anything you desire secure with this Heavy Duty 110dB Siren Alarm Padlock. This innovative U lock comes equipped with two settings, armed and unarmed, so you can be alerted by a 105 - 110 db alarm when the lock is tampered with, basically, double the protection. The Heavy Duty Siren Alarm Padlock has a body made of extra strong cast steel, high-grade steel shackle. It is resistant to corrosion, bad weather, physical destroy & Waterproof.