WatchDog Wireless Aspirated Plant Growth Station (900MHz RadioCommunication) measures Temperature, Relative Humidity, and PAR Light. The Aspirated version includes an aspirated radiation shield for the Temp/RH sensor and the 3668A Full Spectrum PAR light sensor to measure all light sources, including LED. With 1 additional available port, add an extra sensor in addition to those already integrated. View Current Conditions in the WatchDog App and run standard and customized reports with our SpecConnect Cloud Solution Subscription (required with purchase).