I use my TENS unit multiple times a day. I just keep the pads on the entire day and when I feel my shoulders and back pinging, I turn it on for about 20 minutes. At the end of the day, I take the pads off. My unit did come with 3 pairs, but I was going to get the most out of each set. After about 3-4 months of using one set I noticed I wasn’t get the results any longer, it seemed to not be as strong. I did not realize once the sticky wore off, and it wasn’t making a good contact any longer, it wasn’t going to give the results expected. Very happy to have found these. The price is excellent, the quality way above excellent. I feel these have even more sticky than the ones that came with my unit. They also include the plastic covers so I can put the pads back on each night for reuse. They attach just as secure to the TENS wires and provide the relief I need. Excellent purchase!