The following description is reproduced from the 1967 Vox: it's what's happening brochure
A swinging new four string, modified double cutaway solid body bass guitar. Has built-in G tuner, distortion booster, treble and bass boosters. Has an all new easy to fret Fast neck with Vox double T-bar and adjustable truss rod. Fully adjustable bridge. Has the exclusive Vox Ferro-Sonic high output, wide range pick up. Has individual volume and tone controls. Chrome plated machine heads.