Never lose your pen again! I wanted something like this! A pen case that attaches to your notebook. A pen case that attaches to your notebook. It attaches securely with elastic and Velcro. Solves problems like: Pens getting lost in your bag when you need them, Pens falling out even when you clip them to your notebook. Holds 3-4 pens. Supports notebook sizes from approximately 19 to 23 centimeters.