Have a heliflux magnetic aspect sensor type 3

this unit is from 1963 in box .can not find any information on it or what it is worth.any help would be appreciated.thanks
Wha?? This is not Craig's list.
$0.40 tops.
Thanks.was just looking for a little insight.
Glensons, I have to admit I don't know what that device does and can't remember ever hearing of one.

Is it for audio?
Sounds like part of a metal detector.