I just got an old Garmin Edge 520. It seems to work absolutely fine other than it does not connect to my iPhone 13 Pro. My iOS is 15.5 and Garmin firmare
Amazon.com: Garmin Edge 510 GPS Bike Computer (Discontinued by Manufacturer) : Sports & Outdoors
TRAMsoft GmbH - GARMIN Edge 510 (english)
Garmin Connect - Cannot add device Edge 510 - Garmin Connect Mobile Android - Mobile Apps & Web - Garmin Forums