George Martin, the Beatles' record producer, called George Harrison's Rickenbacker 12 string guitar the fab four's "secret weapon." Vox was anxious to cash in on the sudden demand for the twelve string electric guitar and introduced the Phantom XII and Mark XII "Teardrop" guitars in 1964.

Vox expanded on the concept of the original Mark XII guitar by introducing the "Mark XII Special." 

Like the original Mark XII Teardrop guitar, the Mark XII Special featured three single coil pickups, a three position Tele "flip style" pickup selector, and a vibrato arm. The Mark XII Special added six onboard battery powered solid state effects operated by push buttons mounted to the chrome plated pick guard. These buttons actuated the Treble Boost, Bass Boost, Top Boost, Mid Boost, Fuzz and Repeat circuits. A three position rotary control switch toggled between three mid boost frequencies. Additional rotary controls adjusted the Fuzz Sustain (level), Repeat speed, and volume. The volume control also served as an on/off switch.

A round, pleated pad snapped onto the back of the guitar. This pad protected the back of the guitar from scratches and concealed the compartment for the battery that powered the effects.

The neck on this black Mark XII Special was probably made for Vox by Stuart Darkins, a UK based furmiure maker that acted as a guitar part subcontractor for JMI. Vox guitar necks made in the UK had a truss rod cover located on the head stock. Italian (Eko) necks had the truss rod adjustment located at the pick guard.

A hard shell case was included.