This “R” Series has small crenels in the rear part of the vanes. These crenels modify the angle of incidence of the primary airflows, with a subsequent increase of the deporting effect.
The shape of the tail sector has been designed joining up a lithe line without cusps to the shaft, where the arrows are mounted, and this softness of the lines, that are undergone by smaller airflows, ease the rotation of the arrow and limit the energy dispersion. All of this benefits the speed and the stability of the arrow during the flight.
These vanes are especially reccommended for high diameter shafts and indoor competitions, but you can use also for small diameter shafts.