IKEA Picture Ledge, Black, 21 ¾"

Simple little shelf, great for getting some various clutter off of my desk. I don't put anything super heavy on mine but they seem very sturdy. Definitely will be using more of these in the future if I need more floating shelving.

No hardware included for hanging.

I searched a long time for shelves. I bought a bunch at Target and eventually got rid of them in favor of these ones, from IKEA. They are the right depth I need, install easily and flush with the wall, and are sensible weight for picture frames and other light items. From what I can tell IKEA doesn't sell them anymore. Which means you'll pay a little bit of a premium (hence the docked star) but they're the best shelves in this price range I found.