A Key Symptom Of Respiratory Illnesses Is Diminished Lung Function, Which May Lead To Lower Blood Oxygen Levels. If Monitoring Your Blood Oxygen Levels Matters To You, The Braun Pulse Oximeter 1 Makes It Comfortable, Clear And Convenient. Take Readings Effortlessly And Accurately With The Simple Finger Clip Design. See Results At A Glance With The Back-Lit, Rotating Oled Display. And Keep It Close, Always, With The Handy Lanyard Attachment.