I got mine at an alternative health/massage shop. My massage therapist had one and she bought it at the same shop. The pad itself has a thicker plastic exterior than dry heat ones, and it comes with a piece of foam that you wet with hot water and put inside the fabric cover. It really does make a difference. They come in different sizes as well, so I got the one that would cover my whole back.
Seniors Shops They have a regular large one and one specifically for arthritis. The arthritis one is $2 more for some reason, probably because it's for a targetted group. And these ones don't need water. They create their own moisture.
Hugs,
