LBRNO Automatic Anti Bark No Barking Training Shock Vibrate Collar for Small Medium Dog Microprocessor controlled. Voice Recognition feature minimizes false triggering. Humane uses painless tone followed by shock only if barking persists. Automatically increases tone and shock stimuli as barking persists. Extremely small and light weight, adjustable belt length, maximum up to approx. 55cm. Operates on a single long life, 6 volt alkaline battery. The biggest voltage is 13V when shocking. APSD---Automatic Power Saving Mode. More than 2000 times shock and stand by more than 45 days