The SenseAir Sunrise CO2 Sensor is one of the world's lowest power and fully calibrated direct measurement CO2 Sensor.  As low as 45uA average current enabling it to be used in battery operated systems.  The Sunrise CO2 Sensor comes fully calibrated and provides for an automated re-calibration that has a user defined interval.  UART and I2C Interfaces. FREE SHIPPING FOR USA!!  LOW COST INTERNATIONAL SHIPPING!! Sunrise CO2 Sensor used in the Open Source IAQ-LOGR Indoor Air Quality Reference Design.