I just did a little checking around, and it is indeed a latching footswitch setup. It seems that there are Hi Gains with reverb and without. I think you'll need at least one dual footswitch to control both if you have reverb.
Here is the part number for the dual switch at AES...... [FONT=Arial, Helvetica, sans-serif][SIZE=-1]P-H471-LED[/SIZE][/FONT]