Dogtra EDGE 1 Mile Professional Remote Trainer is first Dogtra product that allows the owner to train up to four dogs , giving you the efficiency of training more than one dog . It comes a color-matching collars depending on the number of dogs you want to train so that you can easily determine which dog should provide more training. The collar also has a built-in high intensity LED lights help to find and distinguish dogs easily in low light/dark conditions. Having a wide coverage that can reach up to 1 Mile , this collar is highly recommended for professional and serious amateurs. This collar is best suited for medium to large dogs. It comes with a standard 5/8” contact points that can be extended to 3/4” contact points, for use with dogs with longer coats.