Flojet Portable Self-Priming RV Macerator Waste Pump Kit - 12V [18555000A]Portable Self Priming RV Macerator Waste Pump Kit 12V The Flojet 18555 000 DC portable waste pump is the ideal solution for emptying holding tanks on recreational vehicles and avoiding dump stations. The macerator section grinds waste down to a particle size of 1 8" maximum so it can easily be pumped through a garden hose (5 8" minimum). The pump section is self priming, permitting the unit to be mounted above the tank in a convenient location.