Super reliable and heavily built Neptune Diaphragm Injection pumps will last you a long time. The Neptune pump uses hydraulic oil to actuate a diaphragm which them moves back and forth to meter the fertilizer. The distance the diaphragm moves in controlled by a simple tool-free stroke knob, with settings from 10-100 gallons per hour. All moving parts are constantly submerged in oil and enclosed from the environment, meaning long life and reliability. The most common pump is a the simplex 100 gallon per hour unit (pictured below), but duplex 200 gallon per minute version is also available. We offer these completely set-up with PVC hoses, screen filter, cord, and Banjo Ends or as a bare unit.