Replace your conventional cage nuts with our easy and pain-free /dev/mount, an innovative cage nut alternative. No tools or prior assembly are required for our /dev/mount and no sharp edges need to be touched. Device mounting has never been easier, faster, and safer before. It is compatible with all 19" rails with square punched holes. With the /dev/mount 50-pack, you can fill up to 25 RU, and it comes with longer hex nuts for easier fastening.