FGN J Standard Mighty Jazz, JMJ53ASHDEM Open Pore Blue Bass GuitarCircle Fretting System (C. F. S.) All FGN guitars and basses come with a unique Circle Fretting System (C. F. S.). It was created by FGN based on an idea to offer better pitch and articulation than conventional guitars and basses. All frets are installed on fingerboard in slightly curved shape, so that every string crosses all the frets in 90 degrees, i. e. to offer a minimum contact of string on a fret, and it makes the scale length of every string