Endless Companion Adjustable Pen Pouch - 10 Pens - GreenOne Pouch Fits All It has always been cumbersome to store pens of varying thicknesses in pen holders, until now. With our revolutionary Adjustable Elastic Band, you can store all your writing instruments snugly. In addition to the 10 Pen Slots, the Companion contains a dedicated slot for an additional refill cartridge. The right side also includes a storage pocket for an Endless Storyboard Pocket notebook, documents or any standard pocket notebook.