These are specially designed nuts that can be used to attach equipment or panels to server racks or cabinets that have square holes. They are made of carbon steel and coated with yellow zinc for strength and corrosion resistance. They have a cage-like shape that allows them to snap into the square holes and hold the nut in place. The thread size is M8, which means the diameter of the nut is 8mm. The nuts are compatible with M8 bolts or screws of the same thread pitch. The pack contains 20 nuts, which are ideal for securing your devices or components to your rack or cabinet. For more information, you can refer to the following sources