We had the Petsafe Deluxe Outdoor Bark Control Unit for about 6 weeks and was very disappointed. It did not make any difference to the constant barking of our neighbours dogs. According to the test we did by following the instructions the unit was working but does not seem to make any impact on the barking dogs. Because there is no way of knowing if the ultra sound is actually been send by the unit we can't say for sure if it is working at all. Therefore I am very disappointed with my purchase and will not recommend anyone else to waste there money on this unit.