Designed for getting into fun fast, the Flex Runner 4 is made to be easy for kids to pull on. Its bootie-like design is flexible with stretchy straps that secure their fit. Flex grooves in the outsole allow little feet to move naturally, helping kiddos find their footing. Product Details You spoke and we listened. For the Flex Runner 4, we updated the fit of the midfoot strap and the collar to help make these easy for kids to slip on and comfortable enough to wear all day. Pull tabs on the heel and tongue work with a stretchy inner sleeve to help make these shoes easy for kids to put on themselves. Elastic straps run behind the heel and across the top of the foot to provide a snug, secure feel. Flex grooves in the outsole add flexibility, helping every step feel natural. Multisurface traction works with sturdy foam that wraps around the heel to provide grip and stability when kids shift directions. We reinforced the toe box and used durable materials throughout to help these kicks stand up to how kids play. Soft, springy foam in the midsole helps cushion their every step.