Men's GDEFY Ion Black Slip Resistant Shoes FEATURES VersoShock® patented technology Slip-Resistant Outsole ASTM F2913-11 specially designed outsole provides max grip on any surface. Front Rolling Design designed to reduce foot stress by isolating 28 bones, 30 joints, and over 100 muscles from harm. Roomy Toe Box intended to improve circulation by relieving stress on your toes and arches.