I bought mine through Amazon for $25.00. It has helped me greatly with muscle cramps and twitching. I was woken last night because of twitching. I used it for 10 minutes and the twitching was gone and did not come back. It also helps with the burning for me while I use it but the burning comes back after I stop.

I also bought the separate sock that can be attached to the tens machine. It works but I find it to be stronger. The intensity can be lowered and there are several modes you can choose from but it is still harder for me to use because it almost hurts.

My only issue is my skin in certain spots gets irritated. The irritation goes away eventually. I definitely will trade some irritation for twitching any day