High Tech Pet Bark Terminator Progressive Stimulus Shock Bark Control Collar BT-1 Automatically increases shock stimulus as barking persists Microprocessor monitors the barking pattern and is able to tell the difference between the bark of a dog and stray sounds in the environment Water resistant, rain and snow will not affect operation Weighs only 2-ounce; recommended for dogs over 5 pounds Requires a 6-volt alkaline battery (not included)