[Seattle_Aquarist]

Hi Jeff:,

These links are for 1/2" black sponge filters, not specifically for Eheim. I just purchased these prefilters;
http://www.thatpetplace.com/pet/prod/198263/product.web

Here is a listing of ones for one from another vendor:
http://www.aquariumguys.com/foamprefilter.html

I kept searching under "sponge" and "strainers" until someone posted the term "Prefilter" and then I found them everywhere.