Greenlight Safe Kids GPS tracker

We just switched to this one for my kiddo for the bus/to give them the ability to let us know something's wrong if at a playdate. (Never something we needed to consider in the analog age when kids could use a landline but sometimes kids don't feel comfortable asking the adult in the house to call the parents.) It's really small and can be looped onto anything, and the battery life is great. You can also set up geofencing and get alerts. It's a great price too!