The latest BOSS guitar synthesizer products feature the Serial GK digital interface, a newly developed connection method that delivers evolved performance over the analog 13-pin GK interface used in earlier BOSS and Roland guitar synth and modeling products. The GKC-AD GK Converter allows you to drive the Serial GK input on the GM-800 Guitar Synthesizer from a Roland GK-3 or GK-3B Divided Pickup or an instrument equipped with a 13-pin GK output.