Milwaukee is apparently launching a One-Key tracker called "The Tick" that can be attached to tools and trailers. It's range and requirements are still the same as standard One-Key tools, meaning if there is no one using One-Key in your area you're SOL and even if there are some users your chances of finding it still require them having the app running when their near your tools.   It comes in single units, 4 packs, 10 packs, and 50 packs.