The Potter-Amseco PBA246 is a 6", 24 VAC, vibrating bell ideal for use in fire, burglar, or general signaling devices.The PBA246 mounts easily to a standard 4"x4" electrical box and comes in a red, powder coating. With a low power consumption but surprisingly high decibel rating, the PBA246 boasts incredible power efficiency.The bell is designed for indoor and outdoor use. However, a weatherproof backbox is required to install the unit outdoors. Also known as -Potter Electric Signal Mfg Us POTTER 24VAC 6 BELLS - PL-PBA246