The Draeger 8500 Oxygen/ Carbon Monoxide Dual Sensor Single Gas Monitor has full datalogger, exposure alarms (STEL/TWA) and a powerful battery

Measuring Range: 0 - 25% Vol Oxygen | 0 - 200ppm Carbon Monoxide Resolution: 0.1 Vol% oxygen/1ppm CO

Alarms:
Alarm 1 at 19.5 Vol% | Alarm 2 at 23.5 Vol% for Oxygen (O2)
Alarm 1 at 35ppm | Alarm 2 at 50ppm for Carbon Monoxide (CO)
Warranty: 2 year