A pack of 5 timing shims. These can be used to adjust the orientation of your emitter, for each shim you stack it prevents the emitter from screwing on by a tiny bit more, thus aligning it the way you want.
Timing Shims add material, making the turn stop further counter-clockwise.
Sanding down the female threaded face removes material, allowing the part to turn further clockwise.
So, if your part needs adjusted to screw on LESS, use timing shims, and if it needs to screw on MORE, use this sandpaper.
Less sanding is advised. Sand ONLY a small amount of material off, then check. You can always unscrew and sand a little more, but you'd need to add more shims if you were to sand too much!
5 shims gives you about 180° of counter-clockwise rotation.