The BW Gas Alert Clip Extreme 2 is a hassle-free single gas detector for detecting Hydrogen Sulfide (H2S). Easy-to use, the gas detector requires no calibration, no sensor or battery replacement, and most importantly, no downtime. The gas detector is also water resistant, and features a continuous,alphanumeric, status LCD that shows life remaining, alarm set points andself-test status (audible/visual alarms and sensor, battery, circuit integrity). The gas detector measures 3.2"H x 2"W x 1.1"D, and also includes a test cap, and rugged, stainless steel alligator belt clip for easy portability. Features: - Large confidence LCD displays life remaining in months, days and hours - Displays peak alarm exposures encountered on demand - User-activated daily self-test - Internal vibrating alarm for high noise environments - Records and transmits gas alarm events