Johnson Pump 09-820B F95 Impeller (Neoprene) [09-820B]Impeller Pump: F95 Material: Neoprene (for cooling) Outer Diameter: 3. 74" Inner Diameter: Splines Width: 5. 12" A worn or damaged impeller can cause system failure or engine breakdown. SPX's Johnson Pump brand impellers are developed and manufactured for maximum flow and long life. With a genuine spare impeller you can also be sure that you are getting the quality required by engine manufacturers and professionals. Quick Guide (pdf) Owner's Manual