The Roland GI-20 is a 13-pin USB and MIDI interface, designed for Guitar and Bass controllers equipped with either a GK-2A or GK-2B external pickup, or an internally installed hex pickup with a 13-pin connector.
The GI-20 detects the signal from the guitar or bass source, and allows for triggering of MIDI-equipped samplers and synthesizers, or recording to a computer sequencer as MIDI data. The 1/4" output allows for direct connection to an amplifier, as well.