The ZANIER Heat Technology is based on highly developed textile heat elements and a unique electronic control system. The robust lithium ion batteries which weigh just 60 g provide heat at three different levels for up to ten hours. They are concealed in the HOT.ZX 3.0 cuff and you can hardly feel them. The mittsÂ heating system is easy to operate with a single switch on the battery. The flame shaped light shows the chosen heating level (yellow, orange, red) and shines through the perforated upper material. The supplied USB charger unit recharges the batteries overnight.