The Ridgeline Heavy Base Layer Top is a next-to-skin base layer designed to be worn in more frigid conditions. It features a heavyweight, super soft Merino wool blend that will quickly dry and wick moisture, even during high levels of exertion in the field. The premium Merino is also anti-microbial and retains its insulation value, even when wet. Lighter version also available for more moderate temps (see Ridgeline Base Layer Top).