Carbon Monoxide Inspector/detector - Portable and Handheld - Great for Hvac,travel and Home Use (CO Inspector) Portable, Hand-held, Simple to Use Carbon Monoxide Detector with LCD Display Accurately detect & measure CO gas concentrations from 0 - 2,000 ppm (+/- 2ppm) Large high-visibility LCD display, Long, 2-year battery life Visual and audible alarms, Waterproof and durable construction Designed and made in the USA!, 100% satisfaction guarantee