The type and volume of material to be applied determine the dial and hopper sizes.
Dials come in two styles: standard or high-volume. Five different widths are available to match your specific application: 1/2 inch, 3/4 inch, 1 inch, 1.5 inch, and 2 inch.
Dials are matched to outlet size in the kit plate. The high-volume dial is ideal for larger organic pellets as it allows for 25% more discharge than the standard dial. High-volume dials also allow for the application of 25% more volume of any product when used at the same RPM as the standard dial.
Narrow dials have an output of 300 - 500 lbs per acre. They're generally used with high nitrogen fertilizers popular in conventional farming. Wide dials are for high volume fertilizer and larger pellet types, like fish meal and chicken manure, used in organic farming.