THIS KIT CONTAINS 5 DIFFERENT NOZZLE SIZES 25, 28, 31, 32, and 35. For larger sizes check part #pn21-3747.A wide selection of discharge nozzle sizes is invaluable to properly tune an accelerator pump system. The hole size determines the rate of discharge. A larger hole will shoot fuel at a faster rate with less pressure than a smaller hole. Nozzle sizes are stamped on each shooter (for example, a 25 stamp indicates a hole size of .025).