One dog system with 1/2 mile range,Small receiver (2"x1.5"x1", 2.4 oz) for dogs 5 pounds and larger,Mini ergonomic "stopwatch" transmitter (2.64" diameter x 1.29" thick) is well-suited for small hands or in situations where discreetness is important,Delivers a tapping sensation similar to vibration, but more intense, making it an effective addition to the stimulation,User-selectable stimulation levels from 1 to 100 with additional boost stimulus selectable from 1 to 60,Includes two sets of contact points (5/8" and 3/4"),Lithium-polymer rechargeable batteries with dual charger; 2-hour full charge,