Rain Bird nozzle sets for the 32SA Rotor are designed to save water with even and efficient coverage. Rotors apply different amounts of water depending on the pattern that they are set to water. A rotor set to water just 1/4 of a full circle applies more water than a rotor set to water a full 360, assuming the nozzles are the same. Changing nozzles can help even out the amount of water being sprayed between rotors that are set for different patterns. This will help maintain a healthier lawn and save water.