Riso and Ronga Duplicators are low cost duplicator machines used for high speed, low cost duplications. When printing or copying multiple quantities (generally more than 20) of the same original, it is far less expensive per page than a conventional photocopier, laser printer, or inkjet printer. United Copiers supplies and supports the full range of Risograph and Ronga Duplicators countrywide. Along with excellent pricing , United Copiers offers service and installations countrywide. Simple Rental Options Available.