Specifications: Display mode:LCD Digital Display Measurement method:Oscillographic measurement method Measurement range:Pressure:0~280mmHg (OkPa-37.3kPa) pulse: 40~199 beats /min Accuracy:Pressure: Within+3mmHg pulse:Within+5% Unit:mmHa/kPa Power supply:USB DC5V or 4 pcs AAA batteries(Batteries and USB cable not included) Automatic power off function:Without operation for 1 minute Operating environment:5 ~40°C ,15%RH~80%RH Storage temperature:-20~55°C ,10%~93%RH Weight: About 430g Cuff circumference range:22-32cm. Warm Note Batteries not included. Drinking alcohol or coffee, eating, smoking, exercising and bathing in 30 minutes should be avoided before you take a measurement. Please take a measurement at the same time each day so that the data can be compared in a valuable way.