Readings are conducted at Alveolar level in the lungs where gas exchange occurs There is not a risk of light interfering with the test result. Finger position is not a problem when using a breath activated device. Minimal breath volume is needed for a reading. Skin thickness or color does not interfere with the test results. A breath activated device CAN be used on children. Durable highly visible hardcase and protective sleeve included. Cost of device and disposables are less expensive than other forms of CO measurement No corded finger clip to break or lose. microdot® CO Breath AnalyzerProduct number: 1000-01The microdot® CO Breath Analyzer is supplied with: microdot® CO Breath Analyzer - Product number: 1000-01 22 mm plastic mouthpiece adapter - Product number: 1000-01 22 mm reducing connector for calibration - Product number: 1000-01 PP3 9V Lithium battery (installed) 4 disposable cardboard mouthpieces - Product number: 1000-03 22mm (500 per box) Carry case Operating Manual Orange protective sleeve - Product number: 1000-02 Spec Sheet