How do Crumb dog tags track your dog's location? They claim to track your dog everywhere, but it's unclear if they use GPS technology

Hey people! :paw_prints:how do Crumb dog tags work? Has anyone here used Crumb tags? :earth_africa: How do they track your dog without GPS? :dog: Do they use different technology, and how well does it work? :speech_balloon: Share your insights or experiences with Crumb tags!