Blue Backlight bp Apparatus Best Digital Blood Pressure Monitor Feature:Large LCD size :70*68MM 2x90 groups memory function; Average calculating for the latest 3 times measurement value; Blood pressure classification (WHO) indicator; Irregular heartbeat (IHB) indicator; Year/month/date/time function; Accuracy :Pressure +/-3mmHg; Pulse+/-5%; Power by 4 AAA size alkaline batteries or AC/DC power supply;