Vibram FiveFingers Spyridon MR Women's Running Shoes 4mm Vibram TC1 Performance Rubber Outsole - offers excellent grip, traction and protection for all trail activities Vibram 3D Cocoon nylon mesh - Moulded into the midsole adds a "Rock Block" effect dispersing impact over a wider area. 360 degree lug design - Provides solid grip in all directions on demanding terrain.