Designed with durability and comfort in mind, the GasAlert Extreme reliably monitors for any single gas hazard within its wide range of available toxic gas models. With easy on/off operation, this single gas detector offers extended longevity with a two year field-replaceable battery and sensor. Calibration is a simple automatic procedure and is compatible with BW Technologies by Honeywell's MicroDock II automatic test and calibration system. A wide range of user options, multi-language display and datalogging functionality make the GasAlert Extreme an ideal solution for many applications. Water Resistant.