Sole Material Rubber Outer Material Synthetic Inner Material Textile Closure Type Lace-Up About this Item * White/Plum Chalk-Matte Silver-True Berry Description Nike Metcon Fly knit 3. Women's Training Shoe. Its drop-in midsole works in tandem with firm rubber in the heel to provide durability and stability for high-intensity intervals. Fly knit upper delivers durable, yet lightweight flexibility. Stretch-woven bootie provides a sock-like fit. Firm rubber in the heel provides durability and stability. Synthetic overlays in high-wear areas such as the toe and lateral side enhance durability. Fly wire technology integrates into the laces at the midfoot for a dynamic fit that helps keep your foot in place without restricting natural movement. Sticky rubber in the forefoot offers excellent traction where you need it most. Thin web rubber in the midfoot wraps up from the outsole onto the upper to help resist abrasion. Smoke and pet free.