Inspiration for the Nike Free was found on Stanford University's campus in 2001, when Nike designers observed student-athletes training barefoot. Rated a 5.0/10 on the Free scale, the Nike Free 5.0 is designed to feel halfway between being barefoot and a neutral running shoe. This 'Magnet Grey' edition features an engineered upper with visible Flywire cables for lockdown and a siped foam sole for flexibility.