Greg Schroder from NAFA recommends... I believe,,, a beam that is 2 inches wide at the nose and 8 inches wide, 16 inches down the beam at the shoulders.
If I'm incorrect??
If not I'm not right on that I'm sure someone will jump in and help out. There may be beam size and shape measurements on nafa's site??
Like most things trapping related beams can get personnel according to what one likes. The above measurements I'm sure are meant as a starting point.
I personnaly have two beams, one being much like the above diamentions the other a bit wider.
Both are formed to the curve of my necker.
Mac