Immersion Research Men's Thick Skin Pants are a base layer pant made with soft, plush 29% Greenplus environmentally friendly polyester and 7% spandex a heavy weight, stretchy, single sided fleece. Provides exceptional warmth and keeps you feeling dry. Perfect for cold weather paddling, hiking, xc-skiing, or just about any activity you can enjoy in the cooler months. Flat seam construction to prevent chaffing. Gusseted crotch and hemmed at the ankle for a comfortable fit. Low profile boxer style waistband. Antimicrobial finish. UPF rating 40+ (blocks 97% of UV).