Sescom IL-19 Inline Audio Hum Eliminator

Will this work if used on the main xlr output of my behringer mic mixer/splitter?

Is this for line level or speaker level?

Is connecting this device between my scarlett audio interface and mic cable will eliminate the hum that i'm having?

Can this unit be plugged into the XLT output plug on a bass guitar AMP head then to a XLR cable to the house PA?