The Clairefontaine Twinbook makes it easy to combine two subjects into one notebook. The first 48 pages have a tab cut into them that divides the Twinbook into two sections. Each staple bound notebook contains 48 sheets of beautifully smooth 90g Clairefontaine lined paper. This is a great notebook for fountain pen users. Size: Approx. 8 1/4" x 11" (A4).