High Tech Pet Bark Terminator - Bark Control CollarKey Features: Uses Painless Tone Followed by Shock ONLY if Barking Persists. Automatically Increases Tone and Shock Stimuli as Barking Persists. Small and Lightweight. ANTI INTRUDER Feature Distinguishes Between Nuisance Barking and Alarm Barking. It Allows the More Urgent Alarm Barking if You Choose. Anti howl mode prevents howling. Waterproof Collar. New Bark Sensing Technology Eliminates the Need for an Uncomfortable Vibration Sensor. Extremely