Bundle of 2 items - SportDog - SDF-100A - Underground Inground Fence with PetsTEK Dog Training Clicker and Dog Whistle Training Kit This is a bundle of 2 items: SportDog SDF-100A, PetsTEK Dog Training Clicker and Dog Whistle Training Kit. Wire-Break Transmitter alarm alerts you to possible problems with boundary wire. Built-In lightning protection. Expands to 100 acres with additional wire. Anti-Linger Feature prevents dog from running down Collar Receiver battery in warning zone. Expands to any number of dogs with additional collars. With help of the clicker, you can teach your dog new behaviors with positive reinforcement. Training clicker comes in assorted colors: black, white, green, blue and red. Whistle is another training tool to help stop unwanted behavior and teach your dog to obey commands.