These grills have an optional foam dust filter that lowers noise and keeps dust out, but does reduce airflow some, so I liked that you can use it as is or remove it and do without. Each grill has both a front and back piece, and screws for attaching them are included. Although these are plastic and not metal they feel pretty sturdy, and I like that they add just a bit of height to the fan body with their own thickness added on.A tiny screwdriver is included, but it is too small to actually drive the screws into a fan, it's really just for popping the dust cover frames off, you'll still need a larger screwdriver to attach these to your fans.I'm using these with some USB-powered fans I got a while back to make some very simple cooling stands for various devices like my router, external SSD case, and portable battery pack- all things that benefit from a little cooling. The USB-powered fans didn't come with any grill covers, and the metal kind don't allow you to sit anything on them evenly, so these smooth, flat plastic grills were the perfect thing. With some rubber feet stuck on bottom to lift them up a bit, they turned out just perfectly. I'm more than happy with this set, no complaints at all- 5-stars!