Enhanced functional precision compared with previous models is what characterises the X-BIONIC INSTRUCTOR 4.0 JACKET, thanks to its use of the 3D Bionic Sphere system. The functional jacket cools athletes down when they sweat and warms them up when they are cold. The jacket was developed to provide the full benefits of thermoregulation without restricting movement. The use of special high-tech X-BIONIC thread prevents bacteria and odours, ensuring even greater comfort.