Enter the Behringer 904A VOLTAGE CONTROLLED LOW PASS FILTER Module. A vintage-sounding authentic reproduction of the circuitry from the “Modular 55, 35 & 15” Series from the 70s used by the world’s most famous pop, rock and jazz musicians for their shows. Now, musicians can build their very own, unique, synthesizer that can fit in a standard Eurorack case for a very affordable price. Mix and match specific modules to create your personal, unique synth to complement the music you play or go all out and fill a room, from floor to ceiling, with modules that’ll fulfill any synth geek’s wildest dream.