The TRIPLETT Model GSM120 Portable Carbon Monoxide Meter incorporates a stabilized electro-chemical gas-specific (CO) sensor to measure CO from 0 to 1000ppm. It can be used to check Carbon Monoxide (CO) levels in chimneys/flues， gas appliances (ovens， ranges， dryers)， furnaces， internal combustion engines， portable generators and all coal/wood/charcoal/oil/kerosene/propane/natural gas burning devices. An audible alarm at 35ppm increases beeping until continuous at 200ppm. Measuring Time Mode displays elapsed time from when the meter is powered on and Maximum Hold records the highest reading. Additional features include self calibration in fresh air， manually store/recall 10 readings， backlit LCD display and Auto power off with disable. Includes 9-Volt battery， rubber holster and carrying case. 1-year warranty.

0 to 1000ppm range

Max hold records the highest reading

Audible alarm at 35ppm increases beeping until continuous at 200ppm

Self calibration in fresh air

Stabilized electro-chemical gas-specific (CO) sensor

Measuring time mode displays elapsed time from when the meter is powered on

Maximum hold records the highest reading

Manually store/recall 10 readings

Backlit LCD display

Auto power off with disable