Enhance the page capacity of your current TUL Custom Note-Taking System Discbound Notebook with these expansion discs. The 1" discs offer a 150-sheet capacity, and boast a metallic finish to complement your notebook. Discs let you upgrade your existing TUL Custom Note-Taking System Discbound Notebook's 3/4" discs to increase the page capacity. 1" discs hold up to 150 sheets. Compatible with junior- or letter-size notebooks. Metallic finish coordinates with your TUL Custom Note-Taking System Discbound Notebook (sold separately). These 1" discs hold up to 150 sheets. The original 3/4" discs that come with the notebooks hold 75 sheets.