Incredibly lightweight and waterproof, the Helium Radar Rain Cap combines the waterproof fabric of Outdoor Research's favorite rain jacket with the style and silhouette of their best selling cap. It's just perfect for wet weather performance on the trail, or around town. Lightweight and waterproof Pertex Shield, 2.5L 100% nylon, 30D ripstop shell. Waterproof, breathable, seam taped. Lightweight brim. Reflective logo. External drawcord adjustment. Wicking TransAction headband. Crushable or packable. Wt. 0.4 oz.