Thank you for your email.
I found the Sciaticalm device very beneficial in helping me to deal with my back pain and sciatica. I used it with the larger strap to treat my lower back area. The only slight criticism I would make, is that for treating the back area the strap is very narrow and does not seem to hold the device securely in place. I also think that a wider strap might be more comfortable.
Apart from this, I think the Sciaticalm is a very good device.
Hope this is helpful.