The MSA ALTAIR® 4XR Multigas Detector monitors combustible gases (LEL), O₂, CO and H₂S with rapid‑response XCell® sensors. It’s built for rugged industrial use—survives drops up to 25 ft (7.5 m), rated IP68 for water/dust, operates from ‑40 °C to +60 °C, and comes with a 4‑year instrument and sensor warranty.