Silipos WonderSpur Heel Cups, #4503 X-LARGE Molded, soft, biochemical-grade WonderZorb silicone. Wont dry or bottom out. Hypoallergenic, nontoxic, non-flammable, odorless, and washable. Use in dress or athletic shoes. Heel cushions do not get warmer than body temperature. SIZE X-LARGE Women's: 12+ Men's: 11+