White's Thermal Fusion - Designed by divers and built using Polartecr fabrics, the Thermal Fusion was rigorously tested by professionals to ensure the highest level of comfort and warmth, and independent laboratory tests by the Sport Innovation Center (SPIN) validate the Thermal Fusion's superior insulation value. The outer thermal layer is comprised of Polartecr Classicr 200 fleece which provides warmth without weight, high breathability, and quick dry times. The inner layer is made of wicking and breathable Polartecr Power Stretchr Pro for compression, combined with Whites unique ATS (Air Transfer System) to minimize buoyancy and allow for efficient air venting. Together, the lightweight warmth and breathability of Polartecr Classicr 200, and the body-hugging next-to-skin comfort of Polartecr Power Stretchr Pro, result in White Thermal Core Technology's unmatched flexibility, fit and warmth in an undergarment. Download