The BW Technologies Clip Single-Gas Detector Is Your Everyday Companion For Hazardous Environments. It Operates Up To Three Years Maintenance-Free: Just Turn On The Device And It Runs Continuously No Need For Calibration, Sensor Replacement, Battery Replacement Or Battery Charging. That Means Great Reliability And No Downtime. Plus, With The Two-Year Bw Clip For H2s Or Co, You Can Put The Device In A Hibernation Case When You'Re Not Using It For A Week Or More And Extend Its Life By That Period Of Time. Compatible With Both The Microdock Ii And The Intellidox Instrument Management Systems, The Bw Clip Is Engineered To The Highest Standards Of Quality And Reliability, Keeping You Safe And Compliant.