Feel the soothing effect of lighter and at the same time highly functional high-tech underwear. With its moderate compression, the X-BIONIC® ENERGIZER 4.0 SHIRT ROUND NECK LONG SLEEVE MEN fulfils all the wishes of demanding winter sports enthusiasts who want to benefit from outstanding wearing comfort and performance-optimising thermoregulation at the same time. The new 4.0 generation is the first to feature the Retina® ultra-high definition quality for unique accuracy of functionality. The result is an ultra-dense knitted fabric that integrates 13 highly effective technologies. Functional zones with temperature-compensating and protective effects are positioned precisely and support your performance on cool winter days without you feeling constricted. The legendary patented 3D Bionic Sphere® System with ThermoSyphon® technology is more powerful than ever and is active on the chest: A 40 CM2 sweat absorbing surface as well as complex 3D structures and Y-shaped elements maximize air exchange, cool when you sweat, and warm when you are cold - now faster and more efficient than ever. Technologies such as the AirComPlex-Zone on the upper abdomen and the Air-Conditioning Channel® with surrounding Air Guides® support temperature-controlled ventilation under a second layer of clothing. The X-Impact Technology improves the oxygen and nutrient supply to the muscles and thus promotes enduring performance.