An ideal athletic fit to the Atlas top makes this a baselayer with little equal. With Merino's ability to wick moisture, breathe, and keep you comfortable in a variety of warm and cold weather--all without the funk of traditional synthetic baselayers, there's just no reason not to wear an Icebreaker top.

With a close to the body fit, the Oasis Crew from Icebreaker should be one of the elemental baselayers in any active outdoorsman's clothing drawer. Resistant to odor and excellent breathability make Icebreaker's Oasis Crew Long Sleeve Shirt versatile--worn alone or as part of an active layering system. Features include gusseted underarms, flatlock stitching, and forward side seams to avoid chafing under pack straps.