Smart Watch Men and Women 1.95 inch Bluetooth Talking Watch with Heart Rate, Blood Oxygen and Sleep Monitor Fitness Tracker, IP67 Waterproof Sports Smart Watch for Android Ios(Black) - Walmart.com
Polar M400 User Manual
User manual Polar M400 Sports Watch with GPS & Heart Rate 90057191 | PDF- MANUALS.com
Polar M400 HRM Watch | Runnerinn
M400 product support | Polar USA
Polar M400: Running and activity tracking in one (pictures) - CNET