WS-820 Wristwatch BPM with irregular heartbeat detection. Features: * 2-person, 30-time Memory with Date & Time and Average * Fast, Accurate Readings of Systolic and Diastolic Blood Pressures and Pulse * Clinically proven accuracy * Irregular Heartbeat Detection - helps identify this precusor to atrial fibrillation * Large liquid crystal display is easy-to-read * Runs on 2 AAA alkaline batteries (Not Included) * Limited Lifetime Warranty.