Specification: Size: 9.5(H) x 9.3(W) x 3(D)cm, Shackle diameter:9mm. Main materials: Zinc alloy body, chrome finish. 6 button batteries (AG13 included), battery life: 6 months. Two settings - active alarm and inactive alarm. Water Resistance. Description: Simple, low-price and effective security for sheds, garages, bikes, side gates and tool boxes. This Siren padlock will sound a 100 dB alarm for a full 10 seconds whenever its disturbed much more effective than an ordinary lock. Basically, double the protection. The Heavy Duty Siren Alarm Padlock has a body made of extra strong cast steel as well as a high-grade steel shackle.