For A4; 0.8 inch (20 mm) thick; 6 holes (compatible with 46-80-46; 80-80-80 holes); Body: Coatball; Core: Cardboard; This is a binding pillow that can be used to adjust the thickness of the binding. Made of all paper, so it is useful when disposal. In addition, since the back is white, it can also be used as a replacement for the spine. Compliant with the Green Purchase Act ● Products listed in the Green Buying Network (GPN)