Johnson Pump F4 Impeller MC97 I. The impeller is a very important security device. Its task is to pump the water through the cooling system of the engine. But remember that the impeller should be replaced every year. And always make sure you get a Johnson Pump Brand original impeller. Then you'll know it matches your pump exactly. 508 mm Width 22mm Impeller article number 09-1026B Neoprene (for cooling) Replaces Jabsco 673-0001 Europe & USA Specifications for Johnson Pump I09-1026B-1 F4 Impeller MC97: Manufacturer: Johnson Pump Color: Black Features of Johnson Pump I09-1026B-1 F4 Impeller MC97 Material: MC97 (Designed for cooling) Outer Diameter: 50.8mm (2.0 in.) Inner Diameter: 12.7mm (.50 in.) Width: 22.0mm (.87 in.) Package Contents: Johnson Pump I09-1026B-1 F4 Impeller MC97 Johnson Pump 09-1026B-1: F4 Impeller MC97 I09-1026B-1