This book band features a pen holder that effortlessly attaches to your notebook with a clip. Use it in two convenient ways - by inserting a pen barrel or clip. Its design accommodates a wide range of pen diameters, from thin to thick, so you can easily carry all your important notes and pens in one compact package. Plus, with the adjustable rubber band, you can easily attach it to B6 to A5 size organizers and notebooks.