Features: The 110V 120dB Air Defense device delivers ear piercing alerts with 120dB output, ideal for emergencies warnings in large spaces or noisy industrial environments. Featuring a double alert systems driven by high speed motors and bidirectional rotors, this strong aluminum steel alarm ensures penetrating sound transmission through obstacles. Essential for facility managers, security personnel, and safety coordinators in schools, factories, ports, and mining sites requiring stable emergencies notifications. Designed to operate in extreme conditions, it effectively warns crowds during fires, natural disasters, or security breaches across open areas and multi story complexes. Engineered with weather resistant materials and double electric compatibility (110V/230V), this device secure uninterrupted performances for critical public safety applications. Specifications: Component : aluminum+steel Size: about 17x21cm/6.69x8.26inch Supply electric : 110V/ 230V(optional) Reisistance: 100MΩ Package Includes: 1xAlarm device note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.