Thank you for looking. This product is the DMC Super Fin 2XS Blue. It is a fin from a top manufacturer loved by swimmers from beginners to advanced users for training. The size should be good for those around 20.5cm. Since they are soft fins, your feet won't hurt even if you wear them directly. They can also be used for skin diving and bodyboarding. The price is usually around 10,000 yen, but since this is a sample product, I am offering it at a bargain price of 6,500 yen. Shipping will be via Kuroneko Yamato cash on delivery. Please note that this item is also sold at SHORES, located next to Sushiro in Tehiro, Kamakura City. If it is sold out, we apologize.