The Impi SPC-100 Bark Control Collar utilizes static pulse correction to stop your dog barking. Some dogs respond to a sonic or ultrasonic stimulus; some to vibration; some to a spray stimulus (e.g. citronella, lemon etc). Almost all dogs respond to a static pulse correction and stop barking. This is why an electronic bark collar utilizing static pulse correction is widely regarded as the best solution for nuisance barking. Howitorks - The vibration which occurs in the dog throat when barking, triggers the piezzo quartz sensor within the bark collar to emit a static pulse correction through the EzyFit contacts. The correction starts with 2 low level ?reminder? corrections ? a combination of ultrasound and a very low level of static pulse correction ? and increases through a further 5 levels, should the dog persist in barking. The dog will soon associate the 2 reminder corrections with its barking and realize that the way to avoid the further unwelcome correction, is to stop barking. With 7 levels of correction automatically increasing in intensity the dog is empowered to properly set the appropriate correction setting to motivate them to stop barking.Lithium Battery Powered - The Impi SPC-100 Bark Control Collar is powered by a 6v lithium battery. Lithium Ion battery technology offers three times the gravimetric density of nickel metal hydride technology. In simple terms, this means lighter batteries with increased run times. Replacing batteries not only provides the ability to instantly renew the collar receiver's power supply,itlso provides a consistent duration for battery life . With proper use of the on/off switch the Impi Bark Control battery will last upwards of two years!Includes: water,roof, lightweight comfortable bark control module, an EzyFit adjustable black nylon collar, 2 sets of EzyFit contacts for short and long haired dogs, 1 x 6v lithium battery, a test light and an owner?s manual.