the pedal box just adjusts the signal sent from the throttle pedal to the ECU. you can make it more sensitive or less sensitive as the unit has a key pad.
the unit plugs in the back of the throttle pedal.
its main function is to adjust/reduce the amount of hesitation after pressing the throttle pedal, reduce hesitation in RPM dropping after lifting off the pedal and reduce the amount of travel before anything actually happens - the golf has about 1/2" of travel before the RPMs actually rise. also when you change gear the car hesitates slightly before allowing you to apply the power again.
unfortunately this cant be mapped out so needs a separate unit such as this to adjust the pedal feel/sensitivity.