Up for sale is a used, good working Pentium III 550MHz Slot-1 CPU. It comes with the original heatsink. I've blown out the worst of the dust and removed the cooling fan, as the fan was pretty much deceased. You should be able to find a modern 50x50x10mm fan to fit in the clip. This is a Katmai, so better be ready to deal with the heat it generates (generally not too bad for systems built in modern, high-airflow cases).
For a short time, these were often the best CPU older Slot 1 motherboards with early 440BX implementations could support. Many later 440BX boards should have no trouble with it, but a few really early ones might need a BIOS update in order for the CPU to work. I'll leave that up to you to figure out.Buyer pays shipping costs, which are calculated by weight to destination postal code. The cost of international shipping is known to bring a grown man to tears.Thanks for looking!