Thermoflare liner offer exceptional warmth and comfort. Retains as much as 2mm ~ 3mm neoprene. Allows you to feel warm, even after your second swim. The dark part of Thermoflare is hydrophilic (absorbs water). This pulls water in and traps it allowing your body to heat it creating a barrier of warm water. Since it holds the water in place there is less water to re-warm. The lighter part of Thermoflare is a hydrophobic (repels water) hollow fiber. It has a fleece like feel against the skin and has excellent insulating properties adding even more warmth. It is also very fast drying. Multiple vents that releases hot air and prevents air bubbles from forming.