product descriptionfeel 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.x-bionic® energizer® 4.0 shirt round neck long sleeve men energizer® 4.0. highly functional decision layer of generation 4.0. first choice for sports enthusiasts who prefer unlimited comfort, optimal thermoregulation and light compression. only with x-bionic® 4.0: innovative retina® ultra-high-definition technology. provides ultra-high definition texture, ultra-high density function transmission and ultra-high precision body zoning. award-winning, patented 3d bionic sphere® system with thermosyphon® technology. features complex 3d structures of inner and outer air channels. it cools when you sweat and warms when you are cold. aircomplex-zone at the upper abdomen. protects the sensitive area of the solar plexus. locked in warm air insulates optimally in the cold. excess sweat from physical activity is effectively processed. 100% pure swiss engineered. made in italy. 700+ international awards and test wins, 800+ patent registrations for the products with the x.