The Heat Exchanger Balaclava is made with high-performance 320 g fleece and it's designed to be worn with safety goggles. The technology of the heat exchanger captures heat from each exhaled breath and brings the heat back to the body’s core, helping to prevent loss of body heat. Winter Gear from Klein Tools provides ultimate warmth options so you can focus on getting the job done. Covers: Head, Neck, Mouth. Special Features: Removable Heat Exchanger, High-Visibility Yellow Piping. Color: Black with High-Visibility Yellow Trim.