The Astral Filipe Sandal has two features unique to a flip flop style sandal. The first is the G Rubber outsole, designed by Astral specifically to grip wet rocks. G Rubber "pods" are also placed on the inside of the shoe to keep your foot from sliding around the inside of the shoe. No more slip slop in your flip flop! The second feature is the Super Strap, a lightweight, removable strap that when rigged around your ankle turns the Filipe into a secure, athletic sandal capable of much more than your average flip flop.