PSD Underwear Boxer Briefs - Staple NASA are 88% polyester and 12% spandex. They feature a soft microfiber wide elastic waistband that eliminates itching, a breathable cooling micro mesh pouch, a 7-inch inseam, and a polyester and elastane microfiber blend for dynamic comfort and support with no ride or rubbing. They have a breathable athletic feel, a contoured sealed pouch, flex fit flat-lock seams. Tag-less/seamless back. Machine wash cold. Do not bleach. Tumble dry low heat.