3.1 Phillip Lim's open toe slingback mules are crafted of smooth leather. The pair showcases a unique 65mm crescent heel that adds a modern edge to any outfit. Open toe Slips on Leather upper Leather lining Leather sole Imported SIZE Heel height: about 2.5" (65mm). Women's Shoes - Workshop Shoes > 3.1 Phillip Lim > Saks Fifth Avenue > Barneys. 3.1 Phillip Lim. Color: Black. Size: 6.