Last one on the playground is a rotten egg! . . . Get your growing athlete a leg up in the One Jr running shoe.Predecessor: None.Support Type: Neutral to underpronation (supination).Cushioning: Lightweight, flexible response. Surface: Road.Differential: 0 mm.Altra™ recommends that those new to natural running and zero-drop footwear transition slowly by wearing these on shorter runs and gradually building up to regular mileage.Ideal for running, road racing, and everyday play. Designed to improve running form, toe splay, natural stability, push-off, comfort, and healthy foot development. Quick-drying, breathable mesh upper with thin synthetic overlays. FootShape™ toebox design allows the foot to splay naturally and maintain proper alignment, while absorbing shock and promoting a more powerful toe-off. Lace-up closure. Slightly padded tongue and collar. Breathable textile lining supplies a great in-shoe feel.Removable 5 mm Contour insole. Dual-layer EVA midsole features A-Bound™ top layer that absorbs impact and rebounds energy with each stride. InnerFlex™ technology adapts to foot's natural flex by employing omnidirectional flex grooves in the midsole. Fully cushioned Zero Drop™ technology promotes a more natural foot strike and a more efficient stride.Rubber outsole with FootPod™ technology. Total Stack Height (total thickness of midsole and outsole underfoot): 17 mm.Imported. Measurements: Weight: 4 ozProduct measurements were taken using size 1 Little Kid, width Medium. Please note that measurements may vary by size.