shinfin fins fit very well on tall people with long legs. So, even if you are a tall person about 200 cm (6 feet 6 inches) tall and/or with long legs, the fins will still fit you.
Being tall doesn’t affect how they fit on your legs. This is because the fins fit at the bottom of your legs. Having a long leg length above the fins doesn’t make any difference to how the fins fit your leg. The straps adjust easily to fit around your leg just above your ankle.