Actually, you can use either. There just isn't a special cable listed for the amp because it uses standard 1/4" plugs. A regular Amp Gizmo is recommended with a Mark III - Since the Mark III has one footswitch on the front panel and two on the rear, the Mini Amp Gizmo's 1/4" adapter cable can't reach all three jacks without modification. The Amp Gizmo has individual 1/4" jacks, and you can use them to run individual 1/4" cables to each of the footswitch jacks.