Topo Athletic WOMEN'S ST-3 Size 8 From the manufacturer: ST-3 is our most minimalist road running shoe, with a 16 mm, 0- drop platform perfect for speedwork, tempo runs and gym work. The blucher style provides a snug and secure fit through the midfoot. Strategically placed rubber on the outsole enhances traction and durability where needed. ST-3 features a collapsible heel, allowing them to fold down, making them perfect to throw in your gym bag or as a travel companion. Unit B