MFC Freewave fins are used by many board companies as their OEM fin. MFC say..

The new freewave has been updated with a straight leading edge for the first 10-12cm of the base to help the fin accelerate quickly, get planning early and achieve maximum speed. We have designed it with less tip than a classic freewave but in square shape that helps keep the surface area bigger. This shorter tip allows for less drag at maximum speed. The profile of the fin has been modified on the second half of the fins, from center to tip to provide more flexibility of the G10.

Sizes: 21, 23, 25, 28, 30, 32, 34cm.

25cm is an older model (G10) hence the discount.