Product Description: The Triplett GSM350 is a professional-grade Carbon Monoxide (CO) meter designed to quickly and accurately detect CO gas concentrations in residential, commercial, and industrial settings. Featuring an electrochemical sensor and a dual-line backlit LCD display, it measures ambient CO levels up to 1000 ppm. Equipped with adjustable visual and audible alarms, max hold, and data logging functions, it is an indispensable safety tool for HVAC technicians, building inspectors, and home safety audits.