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 Bottoms use 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 Gusseted Crotch UPF 30 Flat-Seam Construction 53% Merino Wool / 42% Polyester / 5% Lycra | Outdoor Research Alpine Onset 150 Bottoms Men's 2027 - Large Gray | Wool/Lycra/Polyester