Welcome, we are committed to producing high-quality Reverse osmosis self-priming pump.Self-priming pumps are used in environments where there is no water inlet pressure or the water pressure is less than 0.5kg. Self-priming pumps can be used instead of booster pumps or stabilized pumps.Self-priming pump is suitable for reverse osmosis system and aquarium.DeliverySelf-priming pump X 1Adapter*1Wiring *1Elbow*2If you need other types of power ports, you can email usnotes;Manual measurement There is a 1-3mm error due to the different colors of the display. It is normal that there is a color difference.