From their website:

The ballet flat, reinvented.

Stylish, comfortable, durable, and foldable. Meet the most versatile flats in the world.

FLEXIBILITY Featuring a unique split-sole and flexible midsole, Tieks are built to mold to the foot and flex with it as you walk. This design also allows the shoes to fold and fit easily into a purse or suitcase, so comfort and style are always within arm's reach.

DURABILITY Thick non-skid rubber outsole patches, in our signature Tiek Blue color, provide traction and shock absorption to keep you grounded with every step. The brown leather midsole is specially treated to be both flexible and durable, allowing the shoe to be folded and unfolded repeatedly.

COMFORT Tieks are made to stretch and mold to your foot for the perfect fit, and the back is cushioned rather than elasticized to ensure they're never too tight on your heel. The insoles feature advanced foam cushioning for all day comfort and long-term wear.

STYLE With 58 Prints, Patents, Classics, and more, there are Tieks for every wardrobe and occasion. Crafted from luxurious Italian leather and textiles, Tieks’ classic silhouette transitions seamlessly from day to night and season to season—so you never have to sacrifice style for comfort or vice versa.