Fender 0062191000 4 button footswitch. Works with the Stage 1000 DSP, Roc Pro 1000, and others. Fitted with a 1/4-inch jack.
Button 1 - Channel Select
Button 2 - Drive 1 / Drive 2
Button 3 - Effects
Button 4 - Reverb
If the ad is up, it's available.