In the words of JHS Pedals:

Are you on the search for scary good tone? Does your
spine tingle at the thought of a tone that can cut through any mix like a
butchers knife? Do you have nightmares about muddy guitars that lack
clarity and create phantom lead lines that no one can hear? Well, dont
stand there frozen by fear, we here at JHS Pedals have a pedal that
gives you the tone that has long eluded your white knuckled grasp: the
Haunting Mids. The Haunting Mids is a frightfully effective
Sweepable-Mids EQ Preamp that can turn any amp or pedal into a ghastly
monster.With its ability to sweep mids and then boost or scoop them,
you can find the tone that haunts your imagination.