HERS MEDICAL designed to be comfortable and easy to use. Once the cuff is placed in the proper position on the wrist, the user presses the start button. The cuff will automatically inflate, then deflate, and give an accurate blood pressure reading in approximately 30 seconds. Record your results and discuss them with your doctor. Monitoring your blood pressure and understanding how to lower it when it's high, is an important part of managing your health. HERS MEDICAL is committed to making high quality, innovative products to meet the needs of you and your family. SPECIFICATION: Measurement Type: Oscillometric. Measurement Range: Pressure 30 - 280mmHg Pulse 40 -199 times/min Accuracy: Pressure:?3mmHg(25℃) Pulse rate: ?4% of reading Inflation Mode: Automatic by electric rolling pump Deflation Mode: Controlled by Fast & Slow valve Pressure Detection: Piezo-Resistive silicone pressure transducer Power Supply: 2 x AAA Batteries Power Saving:Automatic Power Off idling for 2 min. Oper. Temp/Humidity: + 10℃ to +45℃ 10% to 85% RH. StorageTemp/Humidity: -10 ℃to +60℃. 10% to 95% RH Weight of Main Unit; APPROX. 220G(ex.batteries) ExternalDimension: 70(L) X 80(W) X 33.3(D)mm Wrist Circumference: 135-195mm