Hot Spot Advanced Dog Training Collar With Electronic No Bark Control Dog Collar with 7 Levels Button Adjustable Sensitivity Control with Black Nylon Collar, Suitable for Small to Large Dogs Bark-control collar sends harmless static shock to the dog whenever it barks Adjustable nylon collar senses vibration in dog's throat during barking 7 sensitivity levels (1-7) adjustable for the different size of dogs barking Replaceable 6-volt Battery and Low battery consumption Generally recommend for 18-120lbs dogs.