Best Buy: Garmin Vivosmart 3 Activity Tracker + Heart Rate (Small/Medium) Black 010-01755-10
USER MANUAL Garmin vivosmart 3 Activity Tracker | Search For Manual Online
The validity of activity trackers is affected by walking speed: the criterion validity of Garmin Vivosmart® HR and StepWatch™ 3 for measuring steps at various walking speeds under controlled conditions [PeerJ]