SMALLadjustment to the rest probably won't hurt you with the 3rd but that is what makes that little gadjet that I linked too so great,very simple to use.

AND NO,I DO NOT REPRESENT THEM IN ANYWAY,just a great product imo.

The 4rth is totally irrelevant to how well a level will perform,but when adjusting your 3rd,the fourth is the easiest way to get it right because the 3rd is easiest to set off the bar of a slide bar sight and the 4rth can be used to shoot it in.

basically you square the sight with the sight bar on a fixture and then mount on bow.(most stop here but the sight isn't square with the arrow and it is another plane you need to be square with!!!)Then you just adjust the 4rth axis,(sight bar) with the arrow and you are set perfect for any angle shot you wish to take.

I did not twist the level at all.I actually tested this level on a completely level surface at work.I was able to shim the level on 1 end and reset the level with the shim under it and it still be level when I laid it down,proving that the level in the protractor wasn't square with the next plane as I rotated it over.(The level stayed in contact with the surface the whole time)



The level that I made can be spun in a circle on the same surface and show level all the way around.


The 3rd axis has to be set perpendicular to the arrow PERIOD,your grip style comes into that equation and that is a good reason that the 3rd needs to be checked when shooting the bow.The 4rth axis tool does that.