This GS124 is in Excellent Condition.
The GS 124 is not a generic “Dumble style” pedal, rather, it is specific sonic replication of a particular amp.
No bells and whistles; no extra knobs and switches.
What the GS 124 does is match the tone and feel of the amp.
The GS 124 is amp friendly and particularly likes amps that are set blackface clean but that is only the starting point.