The Härkila Heat Waistcoat is made with the brand new Harkila Heat Control Technology which has been developed over time to maintain a perfect temperature and prolong the effective hunting time. The innovative HEAT technology designed by Harkila uses a thin heating membrane to warm your body safely and effectively for maximum comfort and performance. This membrane is powered by a powerbank in the pocket. The Waistcoat is controlled by your smartphone or the button on the upper centre of the jacket, this button has 3 temperatures for manual setting. The membrane can withstand being folded and packed, and it is fast responding. The lining of the waistcoat retains and distributes the heat evenly around the jacket. The Härkila Heat Waistcoat has a soft micro fleece inside collar and thermo poly shield padding as well as stretch comfort panels. This lightweight Waistcoat is ideal for the active hunter.