Robinson Scent Blocker 8th Layer Long Sleeve Polyester Shirt with S3 Silver Cool, light anti-microbial for Ultra versatility alone or as a base layer Lightweight 100% polyester jersey with a crewneck style Thumbholes for easy layering Stabilizes body temperature whether it is warm or cold Technology reduces growth of odor-causing bacteria Lightweight Anti-microbial Thumbholes for easy layering