JINSHI Men's Underwear Soft Bamboo Boxer Briefs 95% bamboo fiber+5% spandex/93% lenzing viscose+7% spandex Please order it via our size chart.Suggestion:go one size up Ultra U-pouch design provides more space for men's private parts without extrusion or constraint Its a steal thin stretchable breathable and Fabric is soft Comfort soft waistband to eliminate pinching and binding Each pair is neatly folded in own little stylish zip locked baggie.Lenzing viscose is an all-natural fiber and famous for its breathability,which is made from the raw wood.