The T.K.O. Zipless Jersey is constructed to disappear. The T.K.O. Zipless Jersey is based on PNS's Mechanism Pro Zipless Jersey. Made from a unique knitted fabric with high stretchability, the jersey allows heat to escape from your skin, actively cooling you down when moving. The T.K.O. Zipless Jersey is made for the warmest days in the high mountains, where heat management is of greater importance than all-out aerodynamics.