SpectrAlert Advance offers the broadest line of outdoor speakers and speaker strobes in the industry. From metal and plastic outdoor back boxes to red plastic housings, to wall and ceiling mounting options, System Sensor SPSRKLED can meet virtually any application requirement. Wall-mount outdoor speakers and speaker strobes can be use indoors or outdoors in wet or dry applications, as well as can provide reliable operation from −40°F to 151°F. Also, these speakers provide a broad frequency response range; low harmonic distortion and maintain a high sound pressure level at all tap settings to provide accurate and intelligible broadcast of evacuation messages. Like the entire SpectrAlert Advance line, wall-mount outdoor speakers and speaker strobes include a variety of features that increase application flexibility and simplify installation. First, field-selectable settings, including candela, speaker voltage and power settings, and automatic selection of 12- or 24-volt operation enable installers to easily adapt devices to meet requirements. In general, System Sensor SPSRK speaker strobes shall mount to a weatherproof back box. A universal mounting plate shall be use for mounting ceiling and wall products. Besides, the notification appliance circuit and amplifier wiring shall terminate at the universal mounting plate. Also, SpectrAlert Advance speaker strobes, when used with the Sync Circuit Module accessory; shall be powered from a non-coded notification appliance circuit output and shall operate on a nominal 12 or 24 volts.