Using NorPro grid blocks saves material and shipping costs, as well as installation time. Grid bars placed on 8" centers with NorPro grid blocks also have 15% more free space than a conventional 6" center installation using cross partition rings. Saint-Gobain NorPro manufactures grid blocks of high-quality Proware™ chemical ceramic material. We can also supply Proware™ ceramic cross partition rings in 3" (75mm), 4" (100mm) and 6" (150mm) diameters.