Back in the 60's everything everyone made was either a fuzz or a Treble Booster. Vox released a range of four effects which the player would plug directly into the guitar/mic etc. The Distortion - Treble - Bass and the Mic Boosters were very unique (and still are), cheaper to make than the pedals and featured a true bypass switch.
This distortion unit is really a early Fuzz Face/Tone Bender variant in disguise and has become extremely sought after by collectors therefore they're hard to find and cost a fortune when you do find one. This is why we like to bring you the hard to find and mega expensive vintage pedals for you to experience without selling off a kidney or two.
The Vox Showroom site has this to say about the pedal " The #153 JMI Vox Distortion Booster "fuzz tone" was also introduced in the November 1965 JMI Vox price list. The steel case sported a dark red painted finish. The booster utilized a battery operated gain circuit driven by two silicon transistors and featured a three-pole power switch that offered true signal bypass. The UK retail price in 1965 was 4£ 4s. The #153 Distortion Booster provided a less costly alternative to the germanium transistor powered JMI Vox "Tone Bender" fuzz tone."