The Driven Hunt HEAT muff is a warm, lined muff featuring Härkila’s HEAT technology, which lets you set the temperature inside to the level you want. The supplied removable belt makes it easy to clip the muff around your waist, so it is always at hand, even when you are busy and on the move. The Driven Hunt HEAT muff is made from a durable fabric of 84% polyester and 16% polyurethane. The fabric has been given a DWR treatment to make it dirt- and water-repellent. Inside, the muff is insulated with 200g Thermo Poly Shield™ Fill wadding and a thick, soft fleece fabric. The muff has a sewn-in HEAT membrane that can be set to 38 °C, 46 °C or 52 °C by pressing a button on the back of the muff. Also on the back of the muff is a zipped pocket containing a waterproof USB plug, for connecting to a powerbank of your choice. With a powerbank of 10,000mAh, the muff can provide its top temperature of 52 °C for approx. 7 hours at an ambient outdoor temperature of 0 °C. To save power, the heat membrane automatically goes into standby once the muff has reached the set temperature. It then turns back on automatically if the temperature falls 1-2 degrees below the set level. The Driven Hunt HEAT muff has a handy zipped pocket at the front for small items. At the rear, the muff has a detachable belt with a click buckle, for attaching the muff around the waist.