- THE ROW ss new spring and summer flip-flop sandals do not have fancy or childish designs. They are simple flip-flop sandals. They are also irreplaceable. I have always felt that the more simple the style, the less careless the material and craftsmanship. That is to say It has a high-quality texture! Upper: cowhide, lining: sheepskin, sole: leather injection molded outsole, size: 35-39 (custom-made sizes 40 are non-refundable),