"What Our Gearhead® Experts Are Saying:""This is a dependable cold-weather staple. The 5-gauge merino knit feels sturdy and warm without being overly heavy, and it regulates temperature really well during active days outside. I appreciate how it resists odor on multi-day trips, and the standard fit makes it easy to layer under a shell or vest.""When cold air settles over the trail and snow crunches underfoot, we reach for the Arch Rock Long-Sleeve Crew Sweater to keep moving in comfort. Royal Robbins crafts this timeless layer from 100% Responsible Wool Standard merino wool, blending heritage style with mountain-ready performance. The durable 5-gauge knit delivers reliable warmth, while merino’s natural breathability and moisture-wicking properties help regulate temperature through shifting conditions. Odor-resistant fibers make it a smart choice for extended trips, and the classic Fair Isle pattern adds enduring character. Built as an insulating layer for active cold-weather pursuits, this sweater is ready for frosty hikes, winter travel, and everything in between."