Bests & Worsts Reviews from Amazon

I have been using a TENS machine for several years to relieve back and knee pain. I paid well over $100 for my original machine which finally wore out. Found this one for far less and it works just as well. There are only two differences (other than the significant savings.) One is that there is no continuous mode - you can set a timer for up to an hour. The other difference is that you can't set A and B to different functions/intensity. Whatever you set up for one is also set for the other. On the more expensive machine, I could set one of the sides lower for more sensitive areas. This is not a dealbreaker for me especially since I could buy 4 of these for what I paid for the other. If this becomes an issue, I'll just purchase a 2nd unit so that I can set different modes or intensities. This unit is also quite a bit smaller and will fit well in my pocket so I can stay mobile while using it. Overall, I'm pleased with the unit - it does what it is supposed to do.