Perfection Evolved. The vest version of our premium ultralight features the same new high-mobility fit and feature set as the jacket and hoodie, minus the sleeves and the drawcord hem. Version 2.0 is more comfortable and mobile, with slightly longer length for added coverage and warmth, and softer fabric to further enhance the comfort.As an ultralight insulating layer, the MicroTherm is thinner than traditional down vests. But that combination of minimal bulk and effective warmth is what makes it special, and is the result of its patented construction and the exceptionally high-loft Premium Goose Down that it holds close to the body for maximum thermal efficiency.