Oxygen is life, and using a pulse oximeter can be an easy and painless way to see if your body is getting enough of it. During our tests of eight fingertip pulse oximeters over eight weeks, including one week with a case of COVID-19, the independently tested Innovo Deluxe iP900AP Fingertip Pulse Oximeter stood out for its combination of reliability, ease of use, and comfort on the fingers of people ranging in age from 2 to 78.