Worn twice outside, both for short times (~an hour). They are incredibly comfortable with the arch support and cushioned foot bed, and they are so well constructed. I just need a half size bigger! Sarah Flint's site says their 37.5 is a US 7.5, but it fits more like a 7. From the company's website: Stylish and comfortable, the Perfect Block Sandal 60 in sand calf leather features a 60mm block heel, arch support, and adjustable ankle straps. Materials: • Supple Italian calf • Leather lining and insole • Functional buckle • Leather outsole with full rubber forepart