Keep your blood-oxygen levels in check with Beurer Instant Digital Pulse Oximeter, PO 30. It provides accurately calculated readings of heart rates and oxygen in the blood. It is especially created for athletes who play sports like mountain climbing, skiing, biking and more in high altitude areas. It is designed to give instant measurement of pulse and blood oxygen saturation. The readings are clearly displayed on a large digital LED screen. The kit contains batteries, and a strap attached to hold it firmly. It is a simple to use handheld, portable device.