Polar M400 Running Watch Bluetooth GPS Activity Tracking White | eBay
Tested Polar M400 Running Watch Bluetooth GPS Activity Tracking Black | eBay
Amazon.com: BoxWave Cable Compatible with Polar M400 (Cable by BoxWave) - DirectSync Cable, Durable Charge and Sync Cable for Polar M400 : Cell Phones & Accessories
M400 product support | Polar USA
Amazon.com: Weinisite Watch Band for Polar M400/Polar M430 Watch Band,Replacement Soft Silicone Band For M400/Polar M430 Sport Watch (Black) : Sports & Outdoors
Tested Polar M400 Running Watch Bluetooth GPS Activity Tracking White | eBay
New Polar M400 options will color your run | TechRadar