Unify's built-in Restrictor effect is a precision band-pass filter, based on cascaded high-pass and low-pass filters. The high-pass filter defines the contour of the bottom end of the pass-band, and the low-pass filter defines the top end.
The High Pass and Low Pass filter sections are similarly structured. Each has a Freq knob to adjust the filter's cutoff frequency (range 20 Hz to 20 kHz), and a pop-up menu to set the number of cascaded filter stages as follows:
You can thus define the roll-off slope separately for the low- and high-frequency ends of the pass-band.
Note if you set the Freq knobs so they overlap (i.e., high-pass Freq higher than low-pass Freq), you will probably hear no sound at all.
The Restrictor's signal processing allows for the uniltered and filtered signals (i.e., the inputs and outputs of the filter cascade) to be mixed, in proportion to the value of the Dry/Wet Mix control:
Checking the bypass checkbox above the Dry/Wet Mix knob is the same as setting the knob all the way to the left. Although you can bypass Restrictor or any audio effect in Unify, the difference is that this bypass parameter can be connected to a Macro Knob.