Humane Contain RX-10 collar and charger included in one complete kit For Humane Contain X-10 electronic fence, Power Pet electronic doors, Sound Barrier and Yard Barrier sonic fences and Radio Mat pet deterrent kits You can add as many RX-10 collars as you like to your Humane Contain X-10 electronic fence to contain any number of dogs Extremely slim, lightweight waterproof collar is designed for maximum pet comfort Rechargeable battery never needs replacement; recharges in about 3-hour