Mephisto Helen Women's Thong SandalsMephisto recommends ordering up a full size for this style since it runs small (for example, if you are a size 6, you may want to choose a size 7). The Helen sandal is a perennial favorite. Leather, patent, or nubuck uppers are made with the finest materials for ultimate breathability and durability. Adjustable buckle for a personalized fit. Cork footbed lined with leather that softens over time for proper heel, arle buckle for a personalized fit.