1998 Flex Fuel?

Hi, new guy here, I have a 98 Taurus and was going to replace the fuel filter. I bought the one Autozone gave me but it was the wrong size, assuming that is it underneath the doors on the drivers side. So, I take it back and they say it must be a "Flex Fuel" which I had never even heard of. Anyway, I'm having a hard time finding one of the things. Where could I get a part number at?

Thanks much