I've been using these HydroTech fins since, basically they were invented. Love the fit. Love the way they "grab" the water. Love the way you can keep the tempo of the kick fast and the silicone is soft on my feet-not the two-toned dual density rubber that basically folds into the arch of your foot. No blisters ever. No foot cramps ever. Never kick out of them or leave them behind on a flip-turn. They are pricey, but the last pair I kept for about 10 years. They didn't wear out. I actually put something heavy/sharp on top of them and ripped them (accidentally-it wasn't premeditated LOL). That was a sad day. Glad they're still available because these fins will always be my absolute favorite. I'm a 59 yo old swimmer, still swim 6k daily, former swim coach and have tried NUMEROUS other fins. These I love. :)