Features: Small size, Light weight, long life, No moving parts, easy to move, High reliability and no pollution Colding side posts with the words Heating side is empty Red wire to positive, black wire to the negative, it generate electricity when the temperature difference happened Specifications: Model: SP1848-27145 Color: As Show Picture Lead Length: about 30CM Size: 40MM * 40MM* 3.4MM 20 degree temperature difference: open-circuit voltage 0.97V, generated current: 225MA 40 degree temperature difference: open circuit voltage 1.8V, generated current: 368MA 60 degree temperature difference: open circuit voltage 2.4V, generated current: 469MA 80 degree temperature difference: the open circuit voltage 3.6V, generated current: 558MA 100 degree temperature difference: open circuit voltage 4.8V, generated current: 669MA The above values are for reference only, the wiring in actual use, and the step-up board, there will be loss of current Package Content: 1x chip