The S521 features a mahogany body bolted to a maple Wizard III neck with a 24-fret rosewood fingerboard with off-set dot inlays. Components include dual Ibanez Quantum humbucking pickups and a fixed bridge. The S521L is a left-handed version. The S520 is a similar model with a tremolo bridge. The S621QM is a similar model with a quilted maple top.