Shopping for back-to-school? These backpacks can fit 2-3 textbooks, paperback books, 1 large binder, 2-3 spiral notebooks, calculator, pens, pencils, a lunch bag, cell phone, and don't forget the MP3 player. Just want one to take out on hiking trips, to the park, or to just have for whenever you might need it? These backpacks will become your immediate side-kick!