This anti bark collar helps your pet learn the difference between good barking (for protection) and bad barking (prolonged and loud). The anti bark collar picks up the vibrations from your pet’s vocal chords as it barks. The vibrations causes the anti bark collar to send an electronic signal to your pet resulting in a static stimulation. Your pet will quickly learn that barking causes the stimulation to occur, and that not barking is the way to avoid the signals. The Vibration Sensor only picks up vocal cord vibrations eliminating unnecessary shock from extraneous noises. Adjustable Collar fits extra small to extra large dogs. ULTRA MIN-E 2090 Anti Bark Collar corrects unwanted barking in dogs as small as 4 lbs up to 40 lbs. DT Systems Ultra E 2090 is a waterproof battery replaceable collar. A unique feature to this bark collar is its data memory; what this does is remember the last setting you had the collar on so that when you activate it again fro training you don’t have to reconfigure it for your pet because it already is. Get the world’s smallest and most versatile no-bark trainer today!