Create another 2 addition settings with your Line 6 M9/M13! This pedal connects to the expression inputs and allows you to switch parameters without the need for an expression pedal. For example, you can switch between a long and short delay time without changing the effect on your M9/M13. This really adds lots of possibilities to your Line 6 product.
I can build this to your custom specifications i.e. Momentary switch, LED, Single switch etc.