Jabsco Impeller Kit - 12 Blade - Neoprene - 3-¾Jabsco 12blade neoprene impeller kit for bronze flexible impeller pumps, designed for cooling, bilge, transfer, and generalpurpose applications. With neoprene blades and a brass insert, this 12blade, splinedrive impeller delivers steady flow and long service life, sized for 3 3 4" diameter shafts (shaft width 1", shaft diameter 3 9 16"). Blade Material: Neoprene blades provide flexibility and durability for steady flow. Number of Blades: 12 blades