Standard features of bw products: • continuous lcd shows real-time gas concentrations • compact and lightweight design makes it comfortable to wear • water-resistant • simple automatic calibration procedure; compatible with Bw microdock ii automatic test and calibration station • full function self-test of sensor, battery status, circuit integrity And audible/visual alarms on start up • bright wide-angled visual alarm bars • built-in concussion-proof boot Gas measuring range resolution H2s 0-100 ppm 1 ppm Co 0-500 ppm 1 ppm O2 0-30.0% 0.1% Combustible 0-100% lel 1 0% Gases 0.5%v/v 0.1%.