Use where customized emitter flows are needed. Vari-Jets combines a threaded barb base, spray cap and flow valve in one unit that is installed the same way as O-Jet Sprayers. Optimal operating pressure: 20 psi Pressure Range: 15 – 40 psi Install on1/2″ poly tubing or stakes off 1/4″ tubing 180 degree spray pattern (other items available for 360 and 90 degree) Throw radius and GPH easily adjusted down to zero with built in ball valve GPH range: 0 – 24 Spray diameter: up to 20 feet