The 2200 Gallons Per Hour motor is sealed off by a mechanical seal design, while the 1600 Gallons Per Hour model has lipseal. The impeller is carefully designed and tested to maximize head and flow. The 4000 Gallons Per Hour features a robust motor design, mechanical shaft seal, high impact ABS plastic and unique threaded port design. Universal base plate and choice of two different ports makes for a simple installation. Removable check valve provided.• Type: Submersible• Voltage Rating: 12 Volt• Flow Rate: 4000 Gallon Per Hour• Port Type: 1-1/2 Inch And 2 Inch Hose• Length: Not Applicable• Width: Not Applicable• Height: 8-1/2 Inch 2200 Gallons Per Hour Motor Is Sealed Off By A Mechanical Seal Design, While The 1600 Gallons Per Hour Model Has Lipseal Impeller Is Carefully Designed & Tested To Maximize Head & Flow Universal Base Plate & Choice Of Two Different Ports Makes For A Simple Installation | Johnson Pump Bilge Pump, Submersible; 4000 Gallon Per Hour | ABS Plastic