D.T. Systems 1125 No Bark Dog Training Collar Vibration sensor only picks up vocal cord vibrations eliminating unnecessary "shock" from extraneous noises or dog's tags; system delivers 1/2 second corrective stimulation; automatic three-second safety delay Completely digital micro-processor system; digital numeric display shows 8 different intensity levels; data memory system saves last used intensity setting Built in magnetic on/off system; magnet built right into the collar clip-no more lost magnets! Ni-mh 4.8 volt rechargeable battery system Adjustable collar fits small to large dogs; completely waterproof Completely waterproof Delivers 1/2 second corrective stimulation 8 different intensity levels Data memory system saves last used intensity setting