Series 4 5 pumps are designed and built to meet your needs for flow rates ranging from 115 - 330 gallons per hour at 250 psi. These PROCON pumps maintain all the quality features and construction of our Series 1, 2, 3 pumps Follow these steps to select the appropriate PROCON model number: Select the appropriate Series number The third character (111A100F11AA) position specifies the series number. There are six series (1 - Brass 3/8" NPT Ports w/strainer, 2 - Brass 3/8" NPT Ports, 3 - Stainless steel 3/8"NPT Ports, 4 - Brass 1/2" NPT Ports, 5 - Stainless steel 1/2NPT Ports, and 6 - Stainless steel 1" NPT Ports) offered within the Procon Rotary Vane Product Line. Select the appropriate Mounting Drive Configuration The fourth character position (111A100F11AA) specifies the mounting and drive configuration. There are five configurations (A - Clamp-on with .188 Double Flat Drive, B - Clamp-on with 1143 Bronze Coupling, C - Clamp-on with 1143-2 Plastic Coupling, E - Bolt-on with single flat drive, N - Bolt-on with key slot drive) to choose from Due to the vast configurations - we have listed only the most popular ones. Please call if you have a specific model or configuration you are looking for.