19' Rack sub-1U Shelf Bracket is a simple bracket designed to mount a piece of plywood, metal, plastic, foam core poster board or other flat material to make a shelf on your audio rack. You can also use it to mount other things.
It's not 1U of space in your rack - it's actually less than 1U. The two mounting holes are located for an outer and centre mounting points on a rack. It can be installed on the 'centre and bottom' holes for the 1U position, or flipped upside down and installed in the 'centre and top' holes.
To attach your flat material shelf, you can use glue, screws, or simply drill holes in the material according to the pattern on the bracket and insert approximately 5mm stakes as pins. The width of your shelf material should be around 428mm for a 19' rack, but racks are notoriously variable, so measure after you've installed the brackets or cut longer and trim down as necessary.