My dog would bark nonstop in another room and if I tried to use the device through the walls or at a distance it would not work, it would not stop him from barking, but if I entered the room in which she was barking and he saw me he would stop barking immediately, and that is without the use of the device. I took the device with me for a walk with my dog thinking if other dogs would bark at him that I could use the device to stop those dogs, but it didn’t work there either, and maybe because I was 20 to 40 feet away but it did not stop those other dogs from barking at my dog. Fortunately, I could control my dog so he wouldn’t bark under those circumstances, but then again, that’s without using the device on my dog. I will try to find my order number and forward it to you when I find it, thanks.
Bottom Line: No, I would not recommend this to a friend