BW GasAlert Max XT II

Detects Oxygen (0-30% O2), Carbon Monoxide (0-1000 ppm CO), Hydrogen Sulfide (0-200 ppm H2S), & Combustibles (0-100% LEL).
Alligator clip for attachment to belts and harnesses.
Continuous LCD shows real-time concentrations.
One button interface for simple operation.
Audible, visual, and vibrating alarms.
Simple automatic calibration procedure.