Burton says about the Midweight Crew
For highly active, high-output days on the skis, trail, rock, or bike, the Women's Zone Long Sleeve Half Zip provides all the benefits of merino wool with strategic ventilation. The Zone features our BodyfitZONE™ construction, which combines lightweight 200gm stretch merino wool with strategically placed merino mesh panels to help regulate temperature during stop-and-go days. A deep half zip aids in dumping heat when you're moving fast, and the gusseted side panels keep the shirt from pulling up while reaching. Flatlock stitching eliminates chafing during day after day of dynamic motion.