Ryka Women's Knock Out Running Shoe 100% Mesh, Neoprene, Synthetic Imported Rubber sole Weighs 9.6 oz Breathable engineered mesh and 3D print toecap combine with molded neoprene and synthetic overlays for comfortable support. Anatomical Precise-Return footbed. Compression foam with RE-ZORB heel crash pad for impact absorption and reflective decal. Durable dual density rubber outsole with strategic flex grooves provide traction on the road or on the treadmill.