Simms Men's Thermal Quarter Zip Base Layer Shirt - The warmest midlayer for cold days, this top adds warmth on its own, or layer it under your favorite jacket to dial in reliable comfort. A grid-fleece interior traps heat next-to-skin. Smooth faced grid-fleece layers perfectly with our baselayers to provide maximum warmth High collar with a quarter length zipper allows for venting and easy on and off 93% polyester 7% elastane finished with antimicrobial and moisture management Style: PG-13314