K-cup under shelf holder

We have reusable k-cups for our Keurig and they were always just tossed in around the coffee mugs. I wanted a better way to store them but couldn't find anything I liked so I made my own. I made this rack to be mounted above the mugs on the underside of the next shelf so they're out of the way and not taking up any extra space. I designed a single row rack that holds 4 cups and a double row rack that holds 8 cups. The pictures show the double. I just used 4 screws from my parts bins to screw it to the shelf. The rack holds reusable and regular single-use k-cups.