This OTICA Blood Pressure Monitor is Fully Automatic digital machine Works on AAA Size Battery also You can use on Micro USB Cable This is a compact fully automatic BP monitor operating on the oscillometric principle for precise measurements and accurate results. It measures your blood pressure and pulse rate with easy one touch operation Along with BP monitoring this product detects irregular heartbeat. Accurate & Simple and Memory Storage Function Backlit LED Show Resullt in Colour according to your Reading This Product comes with 2 years warranty and lifetime support provided by OTICA. This digital blood pressure monitor is guaranteed to meet your standards Cuff Size Arm Circumference 22-36Cm