Carbon Monoxide Detector, Calibration Certificate Type Available Separately, Digital Display Screen Type LCD with Backlight, Features Adjustable CO Warning Level Alarm, Self-Test Feature, Includes Batteries, Carrying Case and Instructions, Maximum Carbon Dioxide Measured Not Applicable, Maximum Carbon Monoxide Measured 999 ppm, Maximum Dew Point Measured Not Applicable, Maximum Oxygen Measured Not Applicable, Maximum Pressure Measured Not Applicable