This is a convenient all-in-one pedal with a buffer, tuner, volume pedal, and expression pedal. The buffer can be switched to true bypass. It works well with HOTONE multi-effects units, but the expression pedal uses a standard TRS jack, so it can also be used with other multi-effects units for volume ←→ wah functions. (It does not have a wah function on its own) Please search for more details. Used only for indoor practice. It's in good condition, but it's not new, so please refrain from purchasing if you are sensitive to used items. The firmware has been updated to the latest Ver.1.2.0 (improves tuning accuracy to ±0.01 cents).