GPS tech (Garmin, Hammerhead, Wahoo, RWGPS, etc)

I (accidentally) read a review online of a GPS only chip thing they make, it doesn't even have a screen but it is a GPS and sends the info back to base somehow.

I can't remember what it was called though I'm afraid, but they definitely make it.

I guess for tracking only. That'd be a sweet option for long TTs.