For sale: Samsung Galaxy Watch 4 smartwatch (The watch is the basic version, not the regular one. Supports Google apps and electronic payments. Operating System: Wear OS, supports Google apps. Supports Google Pay and Google Wallet feature. Size: 40 mm Health: Contains a BioActive sensor to measure (heart rate, ECG, and body composition analysis "body fat and muscle percentage"). Screen: Super AMOLED, one of the best screens in its price range to date. Advanced Health Sensors: Measures heart rate, blood pressure, and ECG. Body Composition Analysis (BIA): Measures body fat, muscle, and water percentage (a Samsung exclusive feature). Accurate sleep tracking, blood oxygen level, and walking/sports tracking.