These are the current best selling sleep trackers at Amazon.

SaleBestseller No. 3
Fitbit Alta HR, Black, Small (US Version)
5251 Reviews
SaleBestseller No. 6
Muse: The Brain Sensing Headband, Black
954 Reviews

Details and pricing last updated at 2019-06-18 at 21:25 . Links and images via Amazon Product Advertising API