GPS tracking?

It reminds me of the Bluetooth key fobs I've heard about before. They work but they're really short range. I couldn't tell much from that eBay link. Is there a review somewhere?

 

There's plenty of GPS tracker devices available. That no-name Ebay one from Hong Kong is really cheapo, $11 bucks, and just won't last very long or be reliable at all probably.

Amazon has them...
https://www.amazon.com/GPS-Trackers/b?ie=UTF8&node=617650011
So think you need to choose a good quality one, with sufficient battery capacity for the time you require, or is hooking it up to vehicle power an option? They do require SIM cards for data transmission, unless want to be following your mark at very close range using Bluetooth? How much cellular data is used, all depends on how frequently you want position updates from it.