From the Blue Book of Guitars:

Instruments previously built in Brea, CA during the early 1990s.
Inventor Curt Roberts and his artist wife, Elizabeth, invented a multi-sided guitar neck as a means to supply guitarists with a number of alternative tunings on a single instrument. AT the 1979 NAMM show, Roberts displayed the first two-neck design with the double neck Eagle. In the early 1980s, Roberts introduced the Roto Neck guitar that allowed the player to play all four sides of the square neck at the same time. The Roto Neck guitar was available in up to 1,100 different combinations with two-, three-, and four-sided necks. It is unknown how many Roto Necks were actually produced.