I just picked these up on Ebay.

Not sure what they're made of but they are ferrous. They measure 1 3/4" X 3 1/2" and are about half as thick as the ones PTPB uses. For $17 and change I figured I'd give them a shot.
Not sure what they're made of but they are ferrous. They measure 1 3/4" X 3 1/2" and are about half as thick as the ones PTPB uses. For $17 and change I figured I'd give them a shot.
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