This Gerbing's electric heated back wrap can provide relief when you are suffering from back pains all day long. The heated belt supports your lower back and gives you soothing warmth for hours. It is powered by a 7V battery with a built-in temperature controller, B7V-2500, which is included and also comes with a single UK charger. The heated kidney belt requires just one battery to operate, but optionally you can order a second battery and dual charger, which means you will have one spare. The slim design of the electric heated belt makes it possible for you to wear it under your normal clothing and enjoy warm muscles and no-one will see you are wearing a heated back wrap. The reflective stripes can also help to make you highly visible to traffic if you want to use the heated back wrap to go running safely in the dark.