If you decide to go with a single-dial oscillating sprinkler, then you may end up struggling with how to adjust the width. It is not that complicated of a process but it is something that novices may need a bit of elaboration on. To start off with, go ahead and turn the adjustment dial to the right to allow the water to throw all the way to the right. From there, move the dial and twist it to the left and it will do the same thing except to the left side of the sprinkler.
However, simply move it to full if to get the maximum distance out of both sides of the sprinkler. Do not overthink this one folks; it really is as simple as it sounds.