Vionic with Orthaheel Technology Women's Alta Mary Jane Slipper blend Indoor/outdoor slipper - fits Medium Width. Twin gore on the vamp for comfort. Plush lining and footbed. Flexible and lightweight rubber outsole with wave-patterned tread helps improve traction. Invented by leading Australian podiatrist- Phillip Vasyli- this shoe features biomechanical orthotic technology that supports your feet and helps realign the lower legs- reducing over-pronation and associated aches and pains.