You plug this to your guitar, connect it to GR-55, then you have a whole lot of sounds and Synth under your finger tips. However, this comes at few cons:
- It does not look very pretty on your guitar
- it is not the easiest to plug, adjust and setup onto your guitar
- Needs a particular cable with 9 pins to plug to the GR-55
However ,huge benefits:
- You can switch between synth and guitar sound or Mix them
- You can control the volume of your Synth
- Switch sound banks without having to touch the GR-55
The GR-55 is a great unit by itself, and the GK-3 is the only way to connect your guitar and it works perfectly and as expected.