The MD-16 from CEA Instruments is a series of single channel, wall-mounted, continuous detectors that are available for monitoring different toxic gases in either low or high PPM levels. These stand-alone, compact gas monitors are enclosed in durable, weatherproof NEMA 4X enclosures and are virtually maintenance-free, the company said. The MD-16 units are easy to install and operate, with built-in audio and visual alarms that are activated in less than eight seconds in the presence of most hazardous gas levels. These alarms can be tested, silenced or reset with the push of a button or from a distance by simply shining a flashlight on the front panel. Auxiliary outputs and LED lights indicate cell failure, power failure and WARNING alarm. The DANGER alarm has a relay contact that can activate external devices. The MD-16 is available for chlorine, carbon monoxide, hydrogen sulfide, sulfur dioxide, hydrogen, nitric oxide, nitrogen dioxide, hydrogen chloride, hydrogen cyanide, oxygen and other gases.