Humane painless tone followed by shock only if barking persists.Automatically increases tone and shock stimuli as barking persist.Microprocessor controlled.Operates on a standard 6 volt battery.Voice Recognition feature minimizes false triggering.Extremely small and light weight.Operates on a single long life，6 v 45LR44 battery.The biggest voltage is 13v，when shocking.Effective on dogs from 5 pounds to 150 pounds.APSD-Automatic Power Saving Mode.More than 2000 times shock，and stand by more than 45 days.Six Modes to adjust the shock sensitivity by pressing +/- keyDimensions: Adjustable Length:20cm to 53cmColor:blackPackage:1 x Anti Bark Pet Dog Training Collar