1.Loud Voice-Safety Alarm Even in harsh environment, it can be kept hooting for 1 minute. 2.Long Service Life, Reliable Quality A. High quality sonorant diaphragm; B. Thin-film technology with water proof and exhaust; C. Unique contact protection process; D. Anti-weather interference material; E. Superior corrosion resistance 3.With simplified mini design, it can be vertically designed; even in narrow space, it can be still installed. 4.Reliable Quality Osun executes ECE Product Standard and specifications of products are designed according to standard of original manufacturer. Technical Parameter ： Voltage：12V Working volt：9－15V Electric current：≤3.5A Operating temperature：－40℃～85℃ Frequency：H 500±20Hz L 400±20Hz Sound level：110±5dB（A) Life：150,000times Diameter：80mm Weight：240g Carton：30pairs Carton measurement：53*33*37cm Net weight：15kg Gross weight：16kg