Only tried on indoors. Kenko Misato-ko are designed to encourage the use of toes with every step. It is said that using the toes helps children develop arches in their feet and promotes brain development. For adults, it can improve bunions and activate the brain. For seniors, it can help keep the brain young. Ingredients: Tatami Omote (surface): Natural Igusa (rush grass) from Kyushu Sole: 40% natural rubber + 60% synthetic rubber Tatami Omote Edge: Olefin resin (environmentally friendly, does not contain vinyl chloride)