Heart Rhythm Disturbances: This unit automatically identifies and alerts you to any heart rhythm disturbances. If detected, a warning symbol will be displayed after the measurement is taken. What You Get: 1 x blood pressure monitor that meets ESH 2010 performance standards, 4 AAA batteries, 1 wide range cuff that fits upper arms with Circumference of 8.7″-16.5″ (22-42cm), 1 Instruction manual, our worry-free 12-month warranty and friendly California-based customer service. Please carefully read the instructions manual before first use to ensure measurement accuracy. Please contact our friendly customer support team if you have any concerns about the device. iHealth