What size is the windshield wiper blade for a 2008 Mazda B-Series?

Just goto a parts store (AUTOZONE, OREILY's, NAPA, etc). Find the aisle with the wiper blades. Normally will be a book that you can look up the size if you know the year and make of your vehicle. If you can't find the book, or you are uncomfortable, just ask a store associate who can look it up for you in the book or, on their computer. You could call them ahead of time, and they can set the right ones aside for you to pick up and pay. They can even put them on for you too.