GR-20 Updater for Bass Compatibility For Product(s): GR-20 This updater makes the GR-20 compatible with basses equipped with GK-2B/GK-3B divided pickup. The tracking capability is the same as the GI-20. Play GR-20's amazing synth sounds and realistic acoustic sounds with your bass. For Operating System(s): MacOSX / MacOS / WindowsXP / Windows2000 / WindowsMe / Windows98 / WindowsNT