These 2D socks are designed to be fitted into drysuits with a lower leg circumference of around 36cm, + / – 10%. (narrow leg)
Important difference is not the shape but circumference ;An important difference is the dimension across the top which determines which type can be fitted to which suit. Measure the ankle of the suit where the new sock is to be fitted. If you measure this flat across and then double it you get the circumference. Ideally the suit should be 1-2cm bigger than the sock which allows the latex to slightly stretch which gives the best finish. If the sock is bigger than the suit you will end up with creases in the latex which will probably leak.
UK shoe size fitting
Small (36.38) – Med (39.41) – Large (42.43) – XL (44.47)