E-BEST Bark Terminator Advanced Bark Control Collar Anti-Bark Dog Training Collar Humane, uses painless tone followed by shock only if barking persists. Automatically increases tone and shock stimuli as barking persists. Effective on dogs from 5 pounds to 150 pounds! Operates on a single, long life, 6 volt GP battery. (Included) Voice Recognition feature minimizes false triggering. Extremely small and lightweight. Water resistant, rain and snow will not affect operation.