System Sensor’s SSM and SSV series alarm bells are low current, high decibel notification appliances for use in fire and burglary systems or other signaling applications. Reliable Performance. The SSM and SSV series provide loud resonant tones. The SSM series operate on 24VDC and are motor driven, while the SSV series operate on 120VAC utilizing a vibrating mechanism. Simplified Installation.For indoor use, the SSM and SSV series mount to a standard 4 inch square electrical box. For outdoor applications, weatherproof back box, model number WBB, is used. Main Features Approved for indoor and outdoor use Low current draw High dB output Available in six-inch, eight-inch, and ten-inch sizes AC and DC models DC models polarized for use with supervision circuitry Mount directly to standard four-inch square electrical box indoors SSM and SSV series come pre-wired
