This is a production which was self-designed and manufacutred by Hualian Electronic Technical Specification: Measurement Part: up arm Measurement Method: Oscillometric with fuzzy method Display: LCD Digital Display Pressure Range: 0~300mmHg Measurement Range: Pressure 40~280mmHg(5.4~34.6KPa) Pulse: 40~160/minute Accuracy/Calibration: Pressure: - 3mm ~ +3mmHg(- 0.4~+0.4KPa) of reading Pulse: - 5~+5% of reading Clock: month date hour minute Inflation: Automatic inflation by air pump Deflation: Automatic liner pressure deflation value Sensor: Semiconductor pressure sensor Power Supply: 6VDC (4 X AA alkaline batteries) Supply: 3VDC (2 X AAA alkaline batteries) Battery Life: Approx 800 uses (alkaline batteries) Power Management: Turn off automatically when there is no operation for 3 minutes, low battery indicator Unit Weight: Approx 280 grams(not including batteries) Unit dimensions: Approx 135(l) X 100(w) X 85(h)mm Cuff Size: arm Circumference approx 220~330mm