feature 1.Portable and easy to use. 2.Manually adjust the interface orientation. 3.The LED display shows both the test value and the bar graph. 4.Low battery voltage indication. 5.Automatic standby. 6.This oximeter contains 2 AA batteries (excluding battery) Product specifications Display: OLED display SP02: Measuring range: 70%-99% Accuracy: ±2% in the 70%-99% phase, not specified (≤70%) Resolution: ±1% PR: Measuring range: 30BPM-240BPM Accuracy: ±1BPM or ±1% Working temperature: 5 ° C -40 ° C Storage temperature: -10 ° C -40 ° C Working humidity: 15%-80% Storage humidity: 10%-80% Air pressure: 70kPa~106kPa Item size: 6.2 * 3.5 * 3.5cm / 2.4 * 1.4 * 1.4inch Package includes 1 pulse oximeter 1 x product brochure 1 x product lanyard 1x box 1 x cloth bag