Dogtra Pathfinder2 Bundle - Full Size Track and TrainAKC, UKC, and PKC approved This Bundle comes with the Pathfinder2 controller and one Full Size Pathfinder2 Track Train dog device. The Bundle Ships Free. The bundle can expand to up to 21 dogs. To add additional dog devices, simply select the size of the system you want (size = the number of dogs devices you want). Example: 1dog system is one handheld and one GPS dog device. 2dog system is 1 Handheld and two GPS dog devices. Please NOTE: Pathfinder2