I just had a flashback to something I remember seeing in a guitar mag in about 91 (it could have been out earlier than that, but 91 is when I started buying guitar mags at age 12). It was a strip of metal designed to be placed on top of a pickup to extend/focus/alter/ruin/enhance [circle all that apply] its magnetic field. It had sort of spike/diamond shapes where each pole piece would go. I can't remember what it was called and I certainly haven't seen one in the wild. Does anyone remember this thing? Did anyone try it? What's the deal with that thing? Now that it's drifted back through my mind I can't go on living until I get to the bottom of this mystery.