Outfitted with rapid-response MSA XCell® sensors, the ALTAIR 4XR Gas Detector is the toughest 4-gas monitor on the market and is backed by a 4-year warranty. HIGHLIGHTS Rugged Survives 25 drops from 4 feet (1.2 meters) (MIL-STD-810G 516.6 Transit Drop 3rd Party Certified) Can survive an incidental 25-foot (7.5-m) drop onto concrete Operating temperature range: -40°F to +140°F (-40°C to +60°C) Reliable Sense gas 2 times faster than the industry average with our XCell sensors 4-year instrument & sensor warranty Confirm compliance quickly with the Bump LED & on-screen checkmark Bump and calibrate with 1/2 the test gas and in 1/2 the time vs. industry average Bump and calibrate at a specified "Time of Day" with your MSA GALAXY® GX2 Automated Test System MotionAlert option tells others that user has become immobile User-activated InstantAlert notifies others of a potentially dangerous situation