Review on DynaCable M6 16mm Industrial Strength 60-Pack: Cage Nuts, Screws, and Washers for Rack Mount Server Cabinet, Shelves, Routers - Zinc Plated, Rust-Free by Sean Burnett

If you buy cage nuts, you probably have a non-trivial life experience with rack components from different vendors, etc. Nuts themselves have slight differences in the size of the holes or the stiffness of the little tabs that hold them in place etc. You've also probably had to work in a closet where the screws are too short (and you'll either get by without washers or work really hard to secure a few threads, etc.), or where the screws break easily, etc. I hope you have also worked with good cage nuts, the ones where the washers do not