The SHEATH 3.21 Dual Pouch Boxer Briefs! In terms of isolation from the thigh region, the Dual Pouch achieves a deeper dimension of comfort via a circular seamed hole that allows for gentle, unobtrusive separation between the penis and testicles. The flashy appearance and inexplicable comfort of SHEATH 3.21 Dual Pouch Boxer Briefs change expectations about mens underwear.