When the fall chill starts to settle in, it's time to reach for the Core Merino 220 Half-Zip. Featuring a midweight, double-layer merino wool blend, it regulates temperature to keep you comfortable from mild early-fall afternoons through late-season cold snaps. Merino wool is also naturally odor-resistant to help maintain stealth, and theirArmorSpun merino wool is reinforced with nylon to make sure it stands the test of time.