Zone 3 Neoprene Heat-Tech Swim Balaclava If you swim throughout the year, you'll want the Heat Tech Balaclava. Designed to fit underneath your wetsuit, it provides a seal between the wetsuit and your head. Comfortable and stretchy, Zone3 use its Heat Tech fleece lining on the sides for extra warmth. This balaclava delivers warmth on even the coldest of swims. The heat tech lining traps air for insulating warmth, so you stay comfortable and focused on hitting your targets. Crafted from high-quality 4mm Yamamoto Smoothskin material, this neoprene balaclava glides through the water and the low drag hydrodynamic design allows you to move fast. Wear under your wetsuit to provide a seal - keeping you warm and comfortable in cold waters.