Xero Men Genesis Sandals - BlackSimplicity in motion. A ready to wear barefoot inspired sandal for travel, walking, hiking, yoga, working out, paddling, even running ultra marathons. Do everything. Go everywhere. Naturally. GENESIS SIZE GUIDE The Genesis sandal fits true to size.* Since the foot is three dimensional, any two dimensional measuring tool, such as a ruler or Brannock device, can only approximate your true shoe size. Manufacturers model their shoes on different foot