The RTR-576 includes an internal CO2 sensor and an external temperature/humidity sensor.
The rated accuracy for CO2 measurements is up to 5,000 ppm and the display range is up to 9,999 ppm.
The Data Loggers in the RTR-500 Series only function as Remote Units. They require one of the following: Base Unit or Hand Held with which to carry out wireless communication. Battery is NOT INCLUDED