What size wiper blades for Ford F-250 XL super duty 4x4 5.4L Triton?

No Year is listed on the question, however:

2009-2011+ = 22" both sides

1999-2008 = 20" both sides

1997-1998 = 22" both sides

1980-1996 = 18" both sides

The attachment/mount is always another issue so always look up exact part numbers for the brand of wiper you decide to purchase. An example is below, however when looking up by vehicle make, model and year you will ensure proper mount and length.