With its moderate compression, the X-BIONIC® ENERGIZER 4.0 SHIRT ROUND NECK LONG SLEEVE MEN meets the demands of discerning winter sports enthusiasts. The new 4.0 generation is the first to offer Retina® Ultra-High-Definition quality for unique functional accuracy. The legendary patented 3D Bionic Sphere® System with ThermoSyphon® technology is more effective than ever and works on the chest: A 40 CM2 large sweat-absorbing surface, along with complex 3D structures and Y-shaped elements, maximize air exchange, cool when you sweat, and warm when you are cold. Technologies such as the AirComPlex zone at the upper abdomen and the Air-Conditioning Channel® with surrounding Air Guides® support temperature-regulating ventilation beneath a second layer of clothing.