Product Description A Cage Nut consists of a square nut in a spring steel cage which wraps around the nut. The cage has two wings that, when compressed, allow the cage to be inserted into the square holes in equipment racks. When the wings are released they hold the nut in position behind the hole. This makes cage nuts easily replaceable. From the Manufacturer A Cage Nut consists of a square nut in a spring steel cage which wraps around the nut. The cage has two wings that, when compressed, allow the cage to be inserted into the square holes in equipment racks. When the wings are released they hold the nut in position behind the hole. This makes cage nuts easily replaceable.