The Aggressor eFire shirt adds powered heat elements to the most versatile and comfortable layering system available. Designed specifically for KLIM mid-layers and outerwear the Aggressor eFire heated base layer traps body heat to ensure consistent warmth for a cold day on the snow. KLIM’s eFire heated technology features two vertical panels on the chest and one vertical panel on the upper back. The heating element includes three heat modes – low medium and high – with long-lasting heating filaments powered by a USB-C charged battery with a hidden zipper battery pocket.