The brushes that came with the Tire Saver (did?does?) are acid brushes used for applying flux when soldering. These are a standard supply house item and should be about 5 or 10 cents each so $2.50 should buy enough to last for quite a while. BOB FREITAS beautiful day in MILL VALLEY,CA USA
PS acid brushes come in sizes 1/4'' to 1/2'' and have many household and workshop uses