Our minimalist Lulu sandals feature a timeless triangular vamp, softly padded leather uppers and our legendary ergonomic Microwobbleboard™ midsoles. The classic pick for those who are limiting themselves to a single new pair a season. Upper Material:Leather Lining Material:Fabric Fastening:Slip-On Sole Material:Slip-Resistant Rubber Technology:Microwobbleboard Standard FOOTBED TECHNOLOGY Launched in our very first sandal ten years ago, our patent-pending, triple-density Microwobbleboard midsole was engineered by two pioneering British biomechanists. Delivering extraordinary comfort, it not only helps absorb shock but can also diffuse underfoot pressure, by instantly increasing the contact area of the foot to the midsole.