The Roctec 500 material is stronger and will give you longer cutting. It’s also the preferred material for your Extended Pressure cutting (90-100k). We recommend using the R-500 when Waterjet cutting with the H2O JET Advantage EP Pump and part line! To help keep the contaminants out of your water and make your nozzles last longer make sure you are using the H2O JET Short Stop Filter!