Green Magnetic Viewing Film 4x6 | Cool Magnets Science Kit | Magnetic Field Detector & Visual Aid for Physics Education | Ideal for Research & Magnetism Demonstrations

Now that i got your attention, this green magnetic field picker upper is a fun toy for the kids when they are playing with magnets. Good for seeing the patterns of magnetic fields, and easy to wipe the pattern off the paper with another magnet. Not sure about finding hidden alien devices, but you never know.

I work in IT and I used to use a larger version of this same type of product but need something smaller. This is incredibly helpful in locating speakers or magnets that assist in putting devices to sleep or lock displays. Sometimes when you are blindly tearing down devices you may have to separate screen from enclosures and it can be helpful to know what is around the area you are prying at.

These sheets are very sensitive, although you do need to use them in a well-lit environment, as the images are inherently pretty dark. Also the film will leave ghost images behind indefinitely after you remove the magnet, so you might want to periodically degauss it by wiping it with a large refrigerator magnet that can hit the entire film in one pass. Sort of like erasing one of those old Magna Doodles.While it's certainly fun to just look at magnets, especially some of the complex ones that use alternating magnetic poles to have magnets that "turn off" by twisting 180 degrees so the magnetic fields cancel, etc. It's also handy for precisely locating magnets that are embedded inside objects, like the magnet in my laptop that holds the lid shut, or pinpointing exactly where the magnets are on cabinet doors so I know where to put a pad of felt to muffle the slam, etc.

My husband loved it

Not useful for daily things, but great for science experiments and entertainment. Probably the most useful thing about it is that it is basically 'x-ray vision' for the eddy current experiment where you drop a high-power cylinder magnet down an aluminum or copper tube and it drops very slowly. With this, you can 'see' the magnet through the tube as it falls. It's also fun to investigate refrigerator magnets and multi-magnet cubes, etc.With this little sheet, I accidentally discovered that putting my rare-earth block magnet on my fridge magnet made an obvious area where the NdFeB permanently overrode the poor little fridge magnet's field forever! :O It didn't stand a chance."What can ferrite do against such reckless Teslas?" --fridge magnet, 2019-2019Update: 2022 and mine still works great, although I haven't used it much. Surprised to see people saying they only work once. Maybe if you pinch the surface between two magnets, or scratch the back, you'll pop the little fluid areas and ruin them? Any way I've kept mine in its paperboard envelope and it seems safe in there.

I bought the following related items together, so I'm putting the reviews together as well for your convenience.A) <Magnetic Field Demonstrator, Student, Value Pack>> 1 star> Pro - cheap.> Con - filings too big & heavy to align with or indicate the flux lines, so you just get "indicators" that clumps together without revealing much insights.B) <CMS Magnetics® 4" x 6" Green Magnetic Field Viewing Film, Fun!>> 3 stars> Pro - a) it really does look very cool, & weird, & psychedelic; & b) shows magnetic strength.> Con - a) but it gives you little bang for the bucks (when including shipping); b) it doesn't show flux lines; c) thin so may be damaged if not careful.C) <American Educational Steric Demonstrator, For Magnetic Line of Force>> 2 stars> Pro - it sort of works, showing the magnetic flux lines.> Con - a) but it's overpriced for its quality; b) flimsily made with thin brittle plastic pieces glued together as if toddlers; c) pointers don't rotate well and are spaced too far, giving very low resolution; d) awkward to handle, & not designed well.D) <Dowling Magnets Mysterious Magnet Tube>> 4 stars> Pro - a) reasonably priced; & b) works surprisingly well showing the flux field.> Con - a) not as good as <3B Scientific Three Dimensional Magnetic Field Lines Device, 140mm x 140mm x 120mm Size, 21mm Hole Diameter> ($174 as of 10/18/13), but doesn't cost as much either; b) without fluid to help counter gravity (like the expensive one above), flux lines droop.>>Conclusions:1) For neat magnetic visual effects, get (B) of above; though methought overpriced, but still affordable.2) For demonstrating magnetic flux lines, get (D) of above for its good value & say ~80% demonstrative effectiveness; unless you can afford the high quality alternative mentioned above.3) Forget (A) & (C).

Works great. Gives you a color gradient for how intense the magnetic field is. Better than the green magnetic paper that only gives you a solid black color of where the magnetic field is.

Not sensitive possibly due to thickness of plastic card. 1st photo shows card on a strong magnet from Sonic care toothbrush. In 2nd photo not able to see stripes of refrigerator magnet. Not much contrast.