The JETRain nozzle works by a divided stream of water being deflected off the back surface of a deflector pin. This surface evenly divides and breaks up the water into mist or irrigation size droplets. If this deflecting surface is damaged, dirty or if the pin is bent or damaged the water will not deflect evenly. Replacement color-coded pins are available for the JETRain nozzles and can be purchased separately. IMPORTANT not to mix different color pins on nozzle, as this will have impact on the spray pattern.