The TRB 4 had a double cutaway ash body with a bolt-on maple neck (24-fret rosewood fretboard with pearl dot inlays). The scale lenghth was 34 inches. Hardware was a solid brass bridge, 2-a-side gold colored tuners. It had 2 stacked single coils (alnico magnets) with active electronics (volume, treble, mid, bass and mix controls). The finish options were: Natural, Brown Satin, Blue Satin or Cherry Sunburst.

Sources of information:

Yamaha.com

Blue book of electric guitars, 9th Edition. Z.R. Fjestad