I ended up buying f ew sets of these subject dividers and so glad I did. They are strong, hold the paper well in the lever arch files.
There is also a useful index sheet for the front of your file. this is instead of labelling each section.
Plus they are as cheap as the card dividers.
Fine for just dividing pages I suppose, I wanted them for use with picture cards stuck onto these by velcro. Stated that they are strong and plastic but they are more flimsy than expected and break at the holes. Though I think they would be fine for just dividers.