Anti ambient light interface and anti motion technology. It has two parameters: SPO2 and pulse rate. When your SpO2 and pulse rate surpass the set limits, an audio warning will sound. 30-250 Bpm pulse rate, auto shutdown if on signal, battery display and low indicator, 70kPa-106kPa air pressure, 70%-99% measurement range, ±1BPM accuracy, two AAA 1.5V alkaline batteries power, 30mA power consumption, 59 x 36 x 34mm dimension, origin China.