Photos 1-3: Examples of using a rivet closure. I tried attaching a rivet to a cover for myself. It seems to work fine just by attaching the rivet. Photos 4-10: Prototype of an M6 system binder. It's only held together with adhesive and not sewn. If you have any requests or changes regarding the shape or structure, please comment. A ticket holder has been added to the left pocket (Photo 10). TNP notebooks can also be placed in the left and right pockets (Photos 7 and 8). If the pens aren't too thick, two can fit (Photos 7-9). Buttons are not attached, but they can be added as shown in Photo 12. The shape of the pen holder can also be made like the one in Photo 12. This prototype is approximately 14.5cm tall, 14cm wide, and 4-4.5cm thick. The prototype's colors are white and red, which may make it difficult to visualize, but please consider it.