Saw a similar picture in another thread and dug this out off the shelves. No ID on it anywhere.
If so, how do you use it properly?
It's a bulk tape demagnetizer, probably the right size for the old 1/2" tape used as computer storage. So, it'll
eradicate magnetization in a zone about an inch above the platen, just pass your object slowly over the
surface for a few seconds. The object must then be pulled a foot or so away before you
can turn off the demagnetizer (or it may get magnetized).
There's some serious current required, and it's likely to have a thermal cutout, so power-on
time should be as short as possible (if the cutout activates due to overheating, go get
a cup of coffee, because it can't be restarted until it cools).
These (or other designs) of demagnetizer are crucial to get tweezers and cutters into shape
for handling small iron objects, like bits of iron foil for a Mossbauer experiment in a high-pressure
diamond cell. It takes a steady hand and a stereo microscope, too, and we kept
a demagnetizer next to the microscope.
If a steel cutting tool picks up shavings, demagnetizing it is a good idea: the surface finish is better
when the swarf drops away.