95% Bamboo Rayon + 5% Spandex Imported Gentle machine wash in cold water. Versatile Performance: Rayon from Bamboo is a kind of cellulosic fiber extracted from natural materials-bamboo. The Bamboo rayon underwear for men is ultra-soft, comfy, smooth, breathable and moisture-wicking Super Soft Fabric: Bamboo rayon material feels ultra cozy and cool on the skin and silky to the touch Contour Pouch Design: Men’s Trunks are design with 3D pouch can make your package more comfortable without any sticky and holds the boys well No Wedgies: One piece clean cut in the back to avoid embarrassed adjustment for better comfort Stay Put Waistband: Soft and wider waistband with great elasticity won't roll or leave marks