NC Metal Raschig Ring (NC-MRR) 1. First generation of random packings, industry experience outperformes fractionation trays. 2. Great strength-to-weight ratio. 3. NC-MRR Direct replacement of the widely used Raschig Ring 4. Size: 10mm. 12.7mm. 16mm. 25mm. 38mm. 50mm. 76mm. 89mm.