"The Boss" E-Collar 1 Mile Big 2 Dog Remote Trainer + FREE INCLUDED Bungee E-Collars FREE SHIPPING Two dog system with 1 mile range Medium/large receiver (2.7"x1.7"x1.2", 4 oz) for dogs 20 pounds and larger Ergonomic "stopwatch" design transmitter allows you to watch your dog at all times Delivers a tapping sensation similar to vibration, but more intense, making it an effective addition to the stimulation Includes 2 Black Full Grip Supply Bungee E-Collars