🌟The side printed with TEC1-12706 is the cooling side, another is the heating side.
🌟Red wire is positive, black wire is negative. Test method: Install the red and black wires of the refrigeration tablet on both ends of 1 cell battery, if you can feel one side is slightly cold and one side is slightly hot, it means that the refrigeration tablet is good!
🌟Note: Please make sure you have installed with a heat radiator on the heating side. Otherwise the overheating will burn it out. When you installing the radiator, make sure to scribble some thermal grease on the surface.