Before the introduction of the MFT/3 series, Festool USA made available 2-meter MFT profiles for those who wanted to build their own large tables. That part number, 488555, was a 2-pack of those 2-meter profiles. It seems her customer only needs one but will take both.
Since the introduction of the MFT/3 series tables, there hasn't been a similar "long profile" available in NA, just replacements for the ones that exist on the current tables.
Tom