ALARM BELL 1.quality management system certification 2.CE 3.professional ALARM BELL Specification:high quality fire bell , use for the industry and building field .can last working for a long time , no Electromagnetic Interference.long life , and nice tone , the largest decibel is more than 100 d/B /1m. Different size available , 3’, 4’, 6, 8’ 10’. ModelVoltageCurrent(A)Frequency(Hz) ...