A custom-ordered cable, where Tip and Ring are split out. If this is used paired with a Helauxy Solo, you can plug the other jack into an Expression pedal to use with your Stomp.
HX Stomp - Tip == FS4/EXP1, Ring == FS5/EXP2
HX Stomp XL - Tip == FS7/EXP1, Ring == FS8/EXP2