Johnson Pump Aerator Head - 8" Spray Bar w/6" Shut OffAerating Heads 2 Piece Assembly: 8" spray bar with 3 4" barb 6" shut off assembly with 3 4" barb and 3 4" Thru Hull Spray head assemblies can be custom made to required fit, size and flow capacity. A variety of shapes, configuration and options allow us to build these aerating heads to your specifications. Multiple shapes, configurations and options enable us to manufacture these inflatable heads according to your specifications. Johnson pump aeration