Samsung Electronics Galaxy Watch 4 Classic 46mm Smartwatch with ECG Monitor Tracker for Health Fitness Running Sleep Cycles GPS Fall Detection Bluetooth. Body Composition Analysis Get ready to crush your wellness goals with body readings right on your wrist. AdvancedSleep / Continuous SpO2 Manage your overall sleep quality for a great night's sleep with an advanced tracker that calculates your sleep score. ECG Be smart about your heart with ECG Monitoring that gives accurate readings. Fitness / Auto Workout Tracking Make the most of every workout with Auto Workout Tracking. Stay motivated by connecting to live coaching sessions via your smartphone or to dynamic Group Challenges with your friends. WiFi, Bluetooth 5.0, and NFC Technology NOTE: This Smartwatch is only compatible wth Android Samrtphones. (Not compatible with Apple iPhones).