I think that was me who posted that. What it is is a high power magnet that's shaped to fit aroun the filter housing. The magnetic feild traps the metal particles to the side of the housing. I have one on the '55, it does work very well. I purchased mine from a Snap-On dealer, but I know that Summit and Jegs carry them. You'll need to get one that fits thee diameter of the filter housing for a proper fit.
There is a picture of mine in my Webshots album, just click on my signature to see it under the pic "Filtermag".
