A 3-year runtime and DualSense™ technology increase worker safety, regardless of bump test frequency, while reducing overall costs. DualSense uses two of the same type sensors for detection of a single gas, virtually creating a backup system for the sensor. This allows bump testing to be determined by the user, rather than a mandated schedule. A 100 dB audible alarm, strobe-emitting LEDs and vibration alarm warn the user of dangerous conditions. Alarm volume can be increased by about 10dB for higher-noise environments with the addition of the optional AlarmAmp™ (#26496). Unit operates on one field-replaceable 3.6-volt lithium-thionyl chloride battery designed to last 3-years in always-on mode.