[Notebook-Like Binder] A5 Kokuyo's Campus Smart Ring binder notebook, 20 holes 8.7x6.2 inches sprial notebook binder has frosted PP Transparent cover, and the maximum capability is 25 sheets loose leaf binder papers. [Smart Ring System] First, make sure the stopper is unlocked. To take off the lock, place your finger through the bottom hole of the lock and push it out to the left. Once you get stuck here, you may grab onto the bottom tabs on the side and pull those out, then hold the lock and pull it up . Second, open the binder rings, press the plastic button on the top. Third, after you have replaced papers, pinch the rings together, the binder will be closed. [Ultra-thin and lock] The thin binder allows you to put the notebook binder into your bag stress-free and save space. Because of the smart ring binder design that is easy to open and close, the slim binder has a lock keeps the rings from accidentally opening, so you can securely carry this notebook in your bag. [360 Fold 180 Lay Flat] Great refillable notebook binders for meetings and classes, they not only lay flat for writing, but the cover flips back to save space on your desk. The slightly wider and frosted cover protects the index tabs from damage and makes them clearly visible. [10 Kokuyo Original Papers] The Campus notebook binder contains instruction pages and 10 sheets of A5 Kokuyo Campus Sarasara loose-leaf paper, each with 28 lines of 6mm dotted lines. The paper is pH neutral and of archival quality. Notebook-like binders have a maximum capacity of 25 sheets. Kokuyo also offers Grid, Plain and Ruled styles of loose-leaf paper.