Multi effects pedals now have a whole bunch of different ways to control them but most expression pedals just don't have the flexibility as they are made to fit multiple systems. The Mission Expression Pedal for Line 6 is designed specifically for the Line 6 products where applicable.

Extra Control, Perfectly Designed:

The issue with a lot of multi purpose expresison controllers is that different systems work in different ways. By crafting the pedals connections, sweep and switch after the unit it was designed for you get the best possible performance. 

One of the great things they added in to this expression pedal was a switch at the toe of the plate like you would find on a Wah Wah. The idea is that this gives you an extra layer of control letting you change patch or effects without taking up more space on the pedalboard. 

Here's What Mission Enginering say about the Mission Expression Pedal for Line 6:

The Mission EP1-L6 connects to the Line 6 device with a single TS cable. TRS cables are not required for Line 6 expression pedals.

TRS expression pedals are not compatible with most Line 6 products. Line 6 specific pedals should be used with Line 6 devices.

Specifications:

• Pedal dimensions are 10″ x 4″ x 3″ 
  
• Weight is 3.2lb
  
• Potentiometer is 10K Ohm Linear
  

• Colour: Black