MASS21 Men's 4 Pack Underwear Breathable Modal Trunk H-Fly Selected Fabric:93% Micro Modal + 7% Spandex,Soft,Breathable,Nature and Eco-friendly The Boxer briefs are thin, airy, soft, easy-drying, stretchy and overall very comfortable for wearing Separate Pouch with Hole Design,keeping man's personal area comfortably and to be an unprecedented freedom of motion and support, held everything in place Comfy Stretch Waistband:Satin waistband,Metallic Look,with attractive MASS21 logo stitched embellishment There will be a string around the hole of underwear in old design,you can take it off if you do not love it,and we have improved it for new design since Dec,2016.The size chart is made by the standard of US Size,you can refer to product description.If you still have any problem,feel free to contact us!