Likely an Oura Ring: https://ouraring.com/ https://ouraring.com/ It sounds like one of the better sleep trackers (and not just sleep) if you aren't bothered by

Likely an Oura Ring: https://ouraring.com/ https://ouraring.com/ It sounds like one of the better sleep trackers (and not just sleep) if you aren't bothered by the whole "send detailed and continuous personal information to the cloud" thing. I'd recommend staying away from that kind of thing, though..