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Polar M400 review: A feature-packed GPS running watch that can also track your steps and sleep - CNET
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Polar M400 Activity Tracker/GPS Running Watch With Heart Rate Sensor! | Gadget Explained Reviews Gadgets | Electronics | Tech
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Polar M400 review: A feature-packed GPS running watch that can also track your steps and sleep - CNET
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Polar M400 review: A feature-packed GPS running watch that can also track your steps and sleep - CNET
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