Designed to be work as a standalone cap or helmet liner, the XGO Heavyweight Performance Watch Cap PH4 is rated for temperatures below 40ºF. Made from heavyweight Acclimate Dry polyester and spandex Tech Face Fleece, this military cap delivers unbeatable heat retention, moisture management, and breathability. With UPF 50+ sun protection and Ag47 anti-microbial finish that inhibits the growth of odor-causing bacteria, this tactical cap is 100% Berry compliant and proudly made in the U.S.A.