F.L.F. creates a deflection of a ski during edging easily, allowing easier and quicker downhill turn with a larger angle. The more edging you do, the longer the length between two contact points, allowing a grip and stability. Also, it is easy to control the speed of skiing with a larger area of edging. （PAT. No.3837716)
This structure is the same structure as the sandwich structure except that both sides of a top sheet are slightly lowered. This is more sophisticated structure compared to sandwich structure in sense that it is more resistant to external shocks.