Polar M400 review: A feature-packed GPS running watch that can also track your steps and sleep - CNET

The feature-packed and waterproof Polar M400 offers a good set of features for beginners and advanced runners a like. It also provides feedback on your daily activities and sleep.

Polar M400 Review, Detailed, Discount Links

Polar M400 GPS & Activity Tracker Watch In-Depth Review

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Polar M400: Running and activity tracking in one (pictures) - CNET

Tech Review: Polar M400 GPS Running Watch - That Shelf

Polar M400 GPS & Activity Tracker Watch In-Depth Review

Polar M400 Review

Tech Review: Polar M400 GPS Running Watch - That Shelf