The Old Faithful Zip Neck from Core Concepts has just about everything you want in a base layer: function, comfort and style. The anti-microbial Polartec Recycled Power Dry fabric keeps you dry, warm and odor-free, and provides 30+ SPF. The top is fitted but not skin tight, and it’s tagless. Old Faithful also comes in Sport Blue and Black, but we love it in bright red Cayenne, with contrasting blue plaid arm vents. 100% polyester.