Fully molded Croslite. Elastic gore. Open-toe silhouette with slip-on design Man-made lining with textured footed Sculpted heel with non-marking outsole. 3.5" heel These are in used condition, there is wear on the inside of the straps, as well as the sole and heel. The discoloration you're seeing on the inside of the strap is not dirt as they have been cleaned and scrubbed by me, but rather wearing down of the material.