Features: 90 sets of storage (2 people), IHB arrhythmia detection, WHO blood pressure classification. Intelligense Pressurization Measurement Mode: Measurement Range: Pulse Range: 40-199 times/min Range error: static pressure:0.4kpa(3mmhg) pulse: within 5% Cuff lengths: 22-42 cm (8.66-16.5 inch) Power supply: DC6v (four AAA batteries) Auto power off: 60s Storage temperature and humidity : Temperature: -20 to 65C Humidity: 10% to 90% RH Using Temperature Humidity: Temperature: 5 to 40C Humidity: 10% to 90% RH relative humidity How to use? 1, keep relaxed before measuring, sit quietly for a while 2, palms up, place the bracelet parallel to the heart 3, palms up, keep the inlet pipe and arteries parallel 4, wrap the bracelet tightly around your arm in the direction opposite, stick together 5, place a finger in it is the most s appropriate 6, keep the bracelet parallel to the heart, palms up 7, press the on/off button, stay relaxed and start measuring.