We offer Penco RivetRite universal shelf framing system in a variety of pre designed kit sizes. If you need a different size or variation you can create your own. Just choose the parts you need and create your own heavy duty storage unit. You can also purchase additional shelf levels to add to an existing shelving unit. We sell particle board that comes is sizes designed to fit our rivet shelving but this can also be used in other shelving units if you need. If you are in need of any sizes or colors that you do not see on our site, we can order them for you, just contact us for more details.