The Moog VX-351 connects to the Voyagers accessory port with the included detachable cable. It houses twenty-one one-quarter inch jacks that are connected to the Voyagers CV and Gate outputs in a CP-251 sized enclosure with an optional rack mount kit. It also includes two 4-way mults and two attenuators. Adding this to your Voyager adds the capabilities of a modular synthesizer. Think: if Voyager = infinite sound possibilities, then Voyager + VX-351 = infinity squared!!!Moog Music