DT Systems' No-Bark Trainer Collar helps to safely eliminate excessive or unnecessary barking from your dog. This mini no-bark trainer features a waterproof collar with a vibration sensor that picks up vocal cord vibrations only so it won't be activated by other dogs' barking or outside noises. Eight adjustable levels of intensity with a 1/2 second corrective stimulation provide quick and thorough training. It also features a data memory system that saves the last stimulation level used for easy and quick recovery. Adjustable collar fits small to large dogs. Includes NiMH 4.8 Volt rechargeable battery system.