The Potter Amseco MBA-6-12 is a vibrating bell designed for use as a fire, burglar, or general signaling device and features a low power consumption and high decibel rating. The MBA-612 mounts on a standard 4" square electrical box for indoor use or on a model BBK-1 weatherproof backbox of BBX-1 deep weatherproof backbox for outdoor applications. Also known as -Potter Electric Signal Mfg Us DC BELL 6 12VOLT - PL-MBA612