What is this? This is a Music Book Clip which is not only widely used to clip guitar sheet music piano sheet music music books or other cookbooks textbook manual sketchbook etc. It is an excellent choice for hands-free reading during your daily musical practice and book-reading. Are there any advantages of the product? Made of metal it is strong and durable not rust or corrode nor will it bend or deform easily. Good finish and won t damage books Convenient to carry and light in weight it can be easily put into a pocket without taking up space. How to use it? Just insert a metal tip into the top of your book to show the page you want to keep open. What should I notice? All size above is measured by manual please allow +/-0.1 inch error.