BriskHeat SRL12121 SRL Silicone Rubber Heating Blanket, Square, 120V, W x L: 12 x 12-Inch

I use this heating mat with a Johnson Controls 419ABC-1C Temperature controller to maintain a very specific temperature in a vacuum chamber to help assist in the desiccation process. With the JC419 i can keep the chamber within +/-3f with the temp controller at a 1f degree differential. I wired it wrong at first so make sure you double check how it goes. Also double check the jumpers. My controller came ready for cooling, i used it for heating so had to switch the jumpers over. Once you get everything squared away with the controller this heating pad works great. I suggest putting the pad on a surface that does not conduct heat as this will make it much less efficient. I used cardboard under mine.

Works great. I have two of these hooked up to my fermentation tank and they heat great. Using a Johnsons A419 controller.