First time working out in the pool with fins that I have not cramped.
I have tried sooo many types of fins and so far these have not caused any problems.

I think TYR Flex fins are an excellent product.  My problem is finding the correct size for my child. I had to send these back b/c they were too small.  She wears a 8.5 - 9 in women's shoes. We ordered 5 - 7 in this fin - which is a men's size.  I am having to return and hoping the 7 - 9 in men's will fit her and not be too big.

My daughter says they are comfortable. She has to use them 3 times a week for swim practice. They have not left any blisters or made her ankles sore. Great product.

Came right on time, it fits perfectly and perform as it is suppose to perform. Very happy with it except for the one only choise of color.

If you wear a size ten shoe then the nines are perfect. they fit nice and tight and they're very nice fins.

I used the fins three times so far to help improve my kicking. They help you to kick from the hip and not the knee. Because of their drag, you use different muscles than when you don't have them on. I have found them helpful in getting a better kick. Most of my laps are dont w.o. the fins.

The thing that isn't so great about them is their size means carrying something big along with all my other paraphernalia.