I have my students to use this to hold their sketchbooks together. 2 or 3 rings have broken apart but it's what I expected for how many I got for the price. These are pretty good.
I bought a box of 100 because I am a teacher and I use these rings all of the time in my classroom. I hope that the company will as quality control to check the ring better because there are many that do not stay closed which means they won’t work well. 1/10th of the rings would not stay clasped. Please fix this problem. We teachers need them.