I have order two barking collars for my two dogs a few years ago and both collars worked immediately. I have a double coat blue heeler and did have a short coat bull arab. The double coat I needed to clipped around the neck and the collar worked better. I didn't find I needed to tighten the collars to keep the device against the dogs neck, the collar would naturally hang and touch skin. Both collars are still working great. The effects on both dogs have never caused my dogs pain just some discomfort when they feel the effects. I have just ordered more batteries, I accidentally submitted two orders, I tried to call the office but no answer. They immediately called me back and cancelled my double order. My funds were returned very quickly also. It was an express post and it arrived the following g week. I recall speaking to the office before purchasing my collars a few years ago and the lady was very helpful. I give this company and their product a 10/10 due to the excellent and friendly customer service and the fact the device works as advertised.