2.98-8.94 C.I.R. 4000 PSI Max. 2500 RPM Max.   Special Engineered Units Geartek offers units with specially engineered functions to meet specific needs for custom applications. 5.98-18.91 C.I.R. 4000 PSI Max. 2500 RPM Max. C Series D/HD Series E/F Series Specialty Pumps/Motors .88-3.90 C.I.R. 3500 PSI Max. 3600 RPM Max.