This is a passive volume pedal for guitars. Due to its variable resistor structure, it can also function as an EXP pedal by using the included insertion cable (TRS to TS x 2). It can be used to control various parameters via the EXP jack of a multi-effects unit or amplifier. Operation depends on the specified resistance value and polarity of the equipment. It has been confirmed to work properly as both a volume pedal and an expression pedal.