Imarku Bark Control Collar Newly Update with 7 Levels Sensitivity Humane, cost-effective and harmless static shock to the dog whenever it barks. Adjustable sensitively nylon collar senses vibration in dog's throat during barking. It can be adjusted to control the sensitivity of the voice, according to the size of the dog There are a total of 7 levels of correction that will be triggered by your dog's successive barks. Increase the robustness and stability, Lightweight receiver perfect for toy or small Breeds. Generally recommend for 18-120lbs dogs.