Please see tech specs for a quick guide on which nozzles to select.
The Fine Nozzles and Coarse Nozzles provide the best spray patterns for vertical or angle optics. The Fine Nozzles offer less flow for controlled application on smaller optics, while the Coarse Nozzles offer faster application on optics larger than 3". While both the Fine and Coarse Nozzles will work for horizontal or near-horizontal optics, the Medium and Regular Nozzles are able to apply First Contact Polymer faster than the Fine or Coarse Nozzles.
*NOTE* It is advised that you familiarize yourself with these spraying techniques before trying on an optical surface. Load some Spray First Contact Polymer Solution into the sprayer, find a discarded cardboard box, and test out a few sprays so you are familiar with how the First Contact Polymer will behave while being sprayed.
It is also advised that you clean out the spray heads and spray bottles with First Contact Polymer Thinner after each use to prevent clogging.