Midori Penholder Band Black is a book band with a pen holder that integrates with the notebook with a clip. You can use the pen holder by inserting either a pen barrel or pen clip. It can be used with a variety of pen diameters, from thin to thick to accommodate a wide range of pens. You can carry your important notebook and pens in one compact package. The rubber band has an adjuster and can be attached to B6 to A5 size organizers and notebooks.