The Mountain Flex Hybrid combines durable Polartec 200 series fleece fabric with Primaloft® Gold CrossCore 40 g/m² insulation. The insulated sections are also covered with a wind-protective outer fabric. And thats not all: the insulation layer features ClimateSync technology, which incorporates star-shaped perforations. When standing still, you benefit from the full insulating power, but during movement, the structure allows moisture and heat to escape efficiently, reducing insulation. Once you stop, the structure shifts back into an insulating state. - Sporty slim fit - Full-length zipper - Chest tab closure lets you ventilate the vest from the front without it flapping fully open - Adjustable hem