VIONIC WILLA SLIP ON FLAT his flat-style loafer combines luxe materials with a seriously supportive, seamless silhouette for all-occasion wearability. Upper: Leather, Velvet or Printed Calf-Hair. Footbed Lining: Removable PU Covered EVA. Outsole: Durable Rubber. Heel Height: 0.57". Vio-Motion Technology is designed to hug your arches and support your feet in comfort. Vionic sandals' built-in orthotic is shown to be effective in helping to treat heel pain (plantar fasciitis).* True to Size Color: Olive suede Fast shipping!