Yon Bárcena's <<yon.apnea>>
writes:

They have just the same price as Will Wings. 180€ plus packing and
post (+20€) 200 USD at current exchange rate. For more info visit:
www.rakedwingtip.wordpress.com.

The so-called raked wingtips (also known as “swept wingtips”) are a kind of
wingtip devices alternative to winglets. Looking to improve the overall
aerodynamic performance of an aircraft, these are intended to delay and move
away the emergence of the wingtip vortices (a kind of whirlwind that is produced
by the sudden encounter of different pressure air flows that run through the
intrados and extrados of the wing and that increase the induced drag of the
aircraft).

Therefore, the goal of these devices is to increase the aerodynamic efficiency
of the wing, which is achieved by reducing and bringing backward the
perturbations generated by the wingtip vortices. This outcome is beneficial in
three ways:

1 - improved handling and control authority at low speed, as it enhances the
twist effect at the wing tips when turning;

2 - improves the characteristics of the stall, which is more smooth and becomes
more progressive, since the wing tips are a key point for stall formation and
spread;

3 - increases overall performance in straight flight, due to reduced induced drag
on the wing;

These aerodynamic improvements are theoretical. What about in practice?; are of
practical implementation in hang gliding?

Flight tests confirm the improved behavior in turning at low speed by reducing
the tendency to stall of the inner plane. The stall is less abrupt and more
predictable, also in straight flight. And the sink rate is improved at low
speeds. All these effects are more evident with VG activated.

We could conclude that rakedtips bring some positive aspects of less demanding
hang gliders closer to high performance wings.