All early G&L guitars have a U-shaped bracket as a string retainer; a super simple contraption improving the string angle for the high-E and B-strings and sometimes even the G-string as on this F-100 Series II w/DFV. This 2nd style SC-3 w/ebony fingerboard from 1987 is the youngest guitar still with a U-shaped bracket. Because just a year later, i.e. in 1988, the U-shaped bracket was replaced by a black Graph-Tech string tree. Whereas all 4-string basses use a disc shaped string retainer, almost all 5-string models kept using the same U-shaped bracket. Examples are this pre-BBE fretless L-5000, maple fingerboard L-5000, and ‘Z-5000’ prototype as well as the BBE-era L-2500 in my collection. Of course there has to be an exception. Whereas the L-2500 has a 3+2 tuning machine arrangement, the short-lived L-5500 came with a 4+1 arrangement and uses a disc shaped string retainer.