Just slip the metal prongs into the top of the book (as shown) to show the page you want to keep open, and it will stay open. If there is a page to flip, just avoid clipping that page. So simple. The original, the best on the market! Made of rigid, 18 gauge, gold-plated, tempered, aircraft steel. Guaranteed not to bend under normal use! It measures 2" x 4" and slips easily in the top of any book, no matter how large or how thick it is. Works great on text books and cook books too.