This is what men wear when they want better performance:the X-BIONIC® ENERGIZER 4.0 LIGHT SINGLET MEN is your perfect basis for improved performance in your favorite sport.Worn either under your sports shirt or on its own, this pleasantly lightweight singlet optimizes your skin-climate management.It cools when you sweat and warms you when you´re cold.ThermoSyphon®, the next generation of the legendary 3D Bionic Sphere® System, is active on your chest and back.It regulates skin climate through the interplay of numerous technologies:Sweat Traps® quickly transport moisture via Air Conditioning Channel to evaporation-intensive areas Compare prices from: X-bionic in Man's Sportswear