Active Phase is a new offering from the Reda Active line that uses innovative PCM (Phase Change Material) technology, a system that interacts with the body and surrounding environment in order to maintain a constant body temperature. This innovative technology activates when the body and the external temperature change, absorbing and releasing heat as necessary, in order to maintain a constant body temperature. Active Phase is the ideal choice for those who do sports and seek a high-performance fabric that is able to enhance physical activity while preventing sudden changes in temperature.