Mons Royal Half Zip Alta Tech is the ideal base layer top for everyday use. A 100% merino piece in a 190 weight, this is marketed as next to the skin base layer but has too many features to be only long underwear. Off-the-shoulder seams are designed to let pack straps ride comfortably with no pressure points, and reflective detailing marks the front for low-light visibility. There's enough drape in this garment to allow another light layer under it, yet it is light enough to accommodate layering over it. With thumb loops, a higher neckline, and a zip vent to mid-chest, this is a four-season, do-it-all, sports wardrobe soldier of a piece. Full-length torso coverage and thumb loops mean you're covered from neck to fingers against the cold.. roll the wrists back, unzip the neckline, and you've got a midweight layer for autumn hiking that wicks, breathes, and insulates even if the weather changes.