Allowing safe shutdown maintenance work in plants and refineries, Detective + has over dozen gas sensor options, with infrared sensors for flammable gas that are immune to poisoning effects. If dangerous gas level is detected, device warns with wailing 104 dB siren and flashing, high intensity LED beacons visible from all angles. Used individually or in groups, it has 60 hr of battery life, 48-char text display, and -20 to 40°C operating temperature range.