White 12-Volt Surface Mount 6 inch x 1.875 inch x 1.25 inch 30-442 6 inch x 2.875 inch x 1.25 inch, features, UL listed for recreational vehicle use. Meets RVIA requirements test and reset button mutes alarm during ventilation. Tests all alarm functions in one easy step. No dangerous gas required to test alarm. Wide operation range 8-16 volts. Avoid most low battery voltage alarms. Fully operational during mute cycle.