Tagg GPS Pet Tracker

This is a new-in-the-box dog GPS unit that attaches to their collar. Check out the box photo for details; you download an app you can sync it with, and can get notifications via text/email if your pet escapes. You register it and sign up to pay an ongoing monthly subscription fee, although it says your first three months of service are included. 

We bought it but have never used it, as our elderly dog shows no interest in hiking off leash (or escaping!). In original box/packaging.