The innovative new AimSafety PM400 4-gas portable monitor brings enhanced convenience and flexibility to gas detection in hazardous environments. The ergonomic PM400 diffusion gas monitor simultaneously detects up to four gases, including hydrogen sulfide (H2S), carbon monoxide (CO), oxygen (O2) and combustibles (LEL). Key Features: Easy-to-read LCD display Single button operation Rugged, high visual housing IP67 dust tight & water resistant 60-day continuous runtime (IR version) IR sensor is immune to poisoning IR sensor use in inert (low O2) environments Event logging Data logging