Our production line starts with the technical nylon and organic cotton we choose; these are industry standards that create a good quality and breathable insole.They are made from high quality, puere leather and are built to last. Each piece goes through partitions of work, they are cut, made into shape, and polished. With attention to work, we guarantee that every insoles are high in quality and also feels good. With comfort and style, YOUKI leather insoles are your all time shoes best friend.