FDA APPROVED TO READ YOUR HEART RATE AND DETECTS TACHYCARDIA OTHER IRREGULARITIES AND NORMAL SINUS RHYTHM IN 30 SECONDS. BLUETOOTH TO YOUR PHONE AFTER DOWNLOADING THE APP. 1ST MONTH FREE FOR READINGS IN APP. PRODUCT HAS NEVER BEEN OPENED. I HAVE ONE OF MY OWN. THIS PRODUCT IS VERY INFORMATIVE AND HELPFUL TO HAVE. ADD THIS TO YOUR EMERGENCY SUPPLIES.