This abrasive nozzle has a locating ring and washer, for use with Flow cutting heads. (If upgrading to the H2O Jet IDE or Edge cutting head, the collar may be removed by pressing it off.) H2O Jet's Standard Grade abrasive nozzles, designed specifically forconsistent performance (reduced clogging), longer/more cohesive streams for tighter tolerances, fast cutting, efficient use of abrasive, and very predictable and consistent performance. Upgrade to the Premium Grade version for long projects calling for uninterrupted cutting. Also consider the 4"" long version for faster cutting with a more precise, longer, more cohesive stream. Please contact us for help getting the most out of your mixing tubes and abrasive!