Worn as a softshell or midweight insulated midlayer, the highly air permeable Proton LT Jacket is adaptable, versatile and designed to manage the dynamic demands of rock, ice and alpine climbing. Advanced material technologies balance wind, weather and thermal protection while allowing air to pass freely in and out. This ability to self-regulate helps prevent vapour accumulation and allows the Proton LT to deliver comfort over a wide range of temperatures, conditions and output levels.