Wireless Dog Fence Containment System with Rechargeable Waterproof Receiver Collar (Extra Collar)

My 5 years old dog barks every time we come to the park. It is especially embarrassing that he barks at kids and runners. I bought this collar to try to stop him. And it did work! There are2 different regimes - dog can either feel the collar shaking or hear the noise. The noise really works! He immediately stops barking!