Steinite Interference Eliminator

[62SY4]

Anybody have and/or use one of these buggers? It gets connected between a non-loop aerial and your set, and the user tunes the low loss condenser to eliminate interference. I picked it up at a flea market about a year ago, and it got lost in a pile of other stuff and resurfaced today. I guess once I recap my Stromberg Carlson 410J I'll try this gizmo out