B Calibration check system uses dual sensors to measure blood pressure, double check each reading and notify you if your heartbeat is irregular Strong and Durable Detects and removes errors caused by movement and breathing to help promote accurate readings BP level bar shows where your readings fall compared to internationally recognized norms Color: As shown on the picture, Sign of Battery Low Voltage, Pulse Display Number, Working Voltage: 6V, Accuracy:±3mmHg(±0.4kPa), Pulse Rate: 40~200 times/min Fully automatic upper arm blood pressure monitor. Clinically tested accuracy. Show