This Electric Heated Vest has a built-in heating module, powered by intelligent heating technology, to provide equal heating on both the front and the back. Its waterproof process design makes it safe and easy to wash. For the vest to circulate the heat inside, you only have to long-press the switch for 3 seconds. This vest has 5 heating zones that offer balance heat distribution. It is made from skin-friendly fabric so it guarantees comfort. The best thing about this vest is that it is very effective in delaying physiological pain, relieving waist pain, and reducing spinal disorders.