The midlayer for people who run warm on the way up. Hollow-core yarns in a zigzag knit trap air where you want warmth and vent where you do not, so it breathes through a climb instead of turning into a sauna. Quarter-zip for dumping heat fast, offset shoulder seams that stay out from under pack straps, and a slim fit that goes under a shell cleanly.

Specs

• Fabric: 5.7-oz 100% recycled polyester jacquard fleece with hollow-core yarns
• Knit: Zigzag-knit pattern increases airflow and minimizes bulk
• Details: Quarter-zip for venting and easy layering · Off-shoulder seams sit comfortably under pack straps · one back-right zippered pocket · Quick-drying woven binding at the back hem and cuffs
• Fit: Slim
• Weight: 249 g (8.8 oz)
• Made in: Sri Lanka · Fair Trade Certified factory · bluesign approved fabric
• Care: Machine wash cold, tumble dry low, do not iron
• Colours in stock: Birch White