Spring skiing or summer camping? The Merino 150 Base Layer Long Sleeve is designed for both due to the versatility and temperature regulating properties of our Merino fabric. We use Raglan sleeves that eliminate shoulder seams, smooth flatlock seams to reduce chafing, and Core Spun Technology for increased durability. But don't fret. You'll still feel the unmatched comfort of responsibly sourced Merino wool directly on your skin.