The senseBook notebook is great for pencil and fineliners. The acid-free 135-page notebook contains a table of contents and numbered pages. Two cover options are available: Red Rubber and Flap, each made with genuine leather and built to last. Customize your senseBook with three paper styles: blank, ruled, or squared. senseBook paper refill inserts allow you to store your ideas without having to replace the entire Flap notebook.