• The type of screen: LCD screen, transflective screen, touch screen, color screen, physical hands, OLED screens;
• The clocks with activity sensor, synchronized with a smartphone;
• The processing power,
• The storage capacity
• Integrated sensors: oxygen level (VO2Max), pedometer, gyroscope, heart rate monitor, camera, GPS chip,
• Sports training applications
• Wireless connectivity: Bluetooth, 3G / 4G, Wifi, NFC chip,
• Charging the battery: by microUSB port, by wireless contact,
• Autonomy: some watches can last up to 3 days without charging them,
• Impermeability: some watches can support up to 50 meters deep,
• Appearance and design: like normal watches, the shape (round or square), thickness and color are also important.
for more info:https://spinoutdoor.com/best-outdoor-watches-under-200/