Single-gas detector. Alarm Set points 2 to 4 ppm. Maintenance-free no sensor or battery changes necessary. Offers extended longevity with a 2-year field-replaceable battery and sensor. Compact, lightweight design with one-button operation. Designed for a range of harsh environments and extreme temperatures. Hibernation mode with case accessory or IntelliDoX. Automated self-test of battery, sensor and electronics. Wide-angle flash, which alerts simultaneously with audible and vibrating alarm. Automatic logging of the 35 most recent gas events and bump test results.