Function lies at the heart of the street-styled Outdoor Research Radar Pocket Cap. The Radar Pocket Cap shields you from the sun with UPF 50+ protection, keeps you dry with the TransAction headband, and stores away in your pocket with the help of the folding brim.Features: Breathable Lightweight Wicking UPF 50+ Folding Brim for Easy Storage Wicking TransAction HeadbandAvg. Weight: 1.8oz (L) Fabric: Supplex, 100% nylon plain weave Measuring Guide: (Measure around head where headwear would fit comfortably)Small: 6 7/8 = 21 5/8" Medium: 7 1/8 = 22 1/2" Large: 7 3/8 = 23 1/4"