BW Clip4 Multi-Gas Detector. Wearable, easy multi-gas detection that's always on; No charging, no battery or sensor replacement, no hassles and lower cost of ownership. Reliably monitors H2S, CO, O2 and LEL. Features a durable and ergonomic design that is compact and lightweight, user-friendly and tamper-proof operation with a single button, intuitive LCD icons and flashing red non-compliance indicators that warn workers that the detector has not been bump tested according to schedule. Unit conducts a daily full function sef-test of sensors, battery status, circuit integrity, and audible/visual alarms. Fully compatible with IntelliDoX docking system (sold separately).