The Hunter Adjustable Arc nozzles come from the factory with a preset arc of 25 degrees.
Prior to setting the left side arc, set the right side arc by ratcheting the riser assembly and aligning the right side of the spray pattern. There is no indicator on top of the nozzle for the right side arc. You will have to look at the front of the nozzle to see where the right stop is located.
The raised dot on top of the nozzle indicates the adjustable left edge of the spray pattern.