The Mechanism Thermal Long Sleeve Jersey remains highly aerodynamic by anatomically fitting to your riding position on the bike. The chest and frontal arm panels are constructed entirely from Swiss-made wind and water-repellent Schoeller fabrics. The back panel is kept soft and highly breathable with M.I.T.I SuperRoubaix fleece. These panels have also been treated with DWR for increased hydrophobic properties in order to prevent moisture absorption.