These fins are made of soft silicone, reducing strain on your feet and fitting any foot shape. The large, wide foot pocket accommodates those with wider or higher insteps. You can kick as if they're part of your body, and they provide more propulsion than you might expect. If you're interested, please give them a try. Retail Price: ¥15,400 Size: L (approx. 27cm) *I usually wear 26.5-27cm sneakers, and these felt a bit loose when worn barefoot. However, they stayed on perfectly when I wore thick winter fin socks. I used them once around January 2024. They've been stored indoors since then. I'm also including DMC Fin Tethers (used once, retail price ¥2,200) from the same manufacturer, which can be used to prevent heel chafing and adjust the size. Thank you for reading to the end.