We use these binders for our procedure manuals in our laboratory They are constantly opened and thumbed through daily pages added pages removed and even dropped from counter height and they are all still in great condition after many years of using them in our laboratory.
Unlike the silver colored binders which are hard to open these binders with the black openers are much nicer to work with; especially for seniors or those with limited use of their hands. I buy only this kind of binder & wish lighter-weight binders with this kind of opener was stocked with these as well.
This is a good sturdy binder that fits my needs. My only drawback is that the inside folder is at an angle so if you have any papers in it when you open the cover the papers fall out. It would be much better if that folder location was cut straight across so that anything put there would stay put.