evo.com | Outdoor Research Long Underwear Bottoms > Layering under a shell for a cold chairlift or a winter summit push? The Outdoor Research Alpine Onset Merino 150 Bottom uses a soft, non-mulesed merino wool blend with flat-seam construction for chafe-free, naturally odor-resistant warmth that moves with you all day. Regular Fit UPF 30 Flat-Seam Construction Naturally Anti-Odor 53% Merino Wool / 42% Polyester / 5% Lycra | Women's Outdoor Research Alpine Onset 150 Bottom 2027 - X-Large Gray | Wool/Lycra/Polyester