Effectively and humanely controls barking when worn. When the vibration of your dog's bark triggers the sensor probe, a burst of lemon-scented spray is emitted to deter the barking. Comes with collar, 6-volt silver-oxide battery, lemon-scented spray control can, and an instruction manual. All-natural lemon scent is safe and effective. Cannot be set off by another dog's bark. The sensor probe cannot be removed or adjusted. Uses a vibration sensor to sense for barking. The nylon collar measures 1.5:H x 2"W x 1.5"D and weighs 3.2 oz. The black, plastic sensor probe is situated on center of collar. The receiver is waterproof, weighs 1.5 oz. and has low battery indicator, low spray indicator, and on/off switch. Uses a 6-volt silver alkaline battery (included). Emits up to 80 sprays per refill. Product notes: Should not be worn with other collars as they may set the collar off. Collar cannot attach to a leash. Not recommended to use for more than 8 hours at a time. For dogs weighing 8 lbs. or more.