This is the blood pressure monitor that also detects a heart arrhythmia. If the monitor detects that your heart beat is 25% slower or faster than its average rhythm, an arrhythmia symbol illuminates on the LCD. It uses the oscillometric method that's clinically proven to detect arrhythmia and hypertension, and it takes three consecutive blood pressure readings and averages the results--a methodology recommended by the American Heart Association for its accuracy. The integrated memory stores up to 30 measurements for four people (120 total readings) that are time- and date-stamped, the cuff automatically inflates and deflates, and its 3 1/3" x 2" backlit LCD shows large, crisp numbers and symbols that are easy to read. Requires four AA batteries. Consult a physician if repeated arrhythmias are detected. 4 3/4" L x 6" W x 2 3/4" H. (14 1/3 oz.)