The Finger Pulse Oximeter Blood Oxygen Saturation Tester is a portable device that uses an infrared sensor to measure the oxygen saturation in your blood. This FDA 510K compliant oximeter is designed features automatic power off for convenience. The sleek blue device operates on batteries and is easy to use, making it ideal for monitoring your health and wellbeing on the go. If you purchase more than 1 Lot check them all out together in one basket at same time combined p&p will adjust automatically.