Vibratone® Vibratone® heavy-duty bell product line utilizes a modular approach to combine gongs and mechanisms allowing for greater flexibility and selection. Three gong sizes are available the model A4 is four inch in diameter, the model A6 is six inch in diameter and the model A10 is ten inch in diameter. Each larger gong produces a different tone and a higher dBA output. Vibrating® bells produce a continuous ringing sound when voltage is applied. The models 500 and 600 vibrating mechanisms are designed for AC and DC operation, respectively. The models 500 and 600 are UL and cUL Listed, Vibratone® bells can be used in any industrial application, whether to signal danger or for start and dismissal. A variety of mounting accessories will accommodate almost any environment.