The StarTech.com® CABSCRWM520 M5 rack mounting screws and M5 cage nuts help in installing rack-mount hardware such as rack-mount hardware such as your server, network or audio/video equipment. Square cage nuts are suitable to use on racks and cabinets with square holes. These nickel-plated screws and nuts in silver color, are resistant to rust. They come with cage nut installation tool.