This will be needed you if intend to use RF remote control or IR extenders.
Well, I personally had some issues with that, I found answer on URC forums (don't have link now but...)
It's a bit below and to the left of first of digits
Approx location on image below
You mean, "How do I stick it on without it falling off?" Zantech sells a wider plastic piece that's vacuum-formed with sticky backing. You can trim it to fit and it usually stays on pretty well, unless the face gets too warm- nothing stays on very well, then. Harmony RF extenders come with a rubber piece that works the same way and I'd like to find out if anyone else sells them separately. The stiffer Zantech plastic has a tendency to want ot go back to being flat and that causes it to pull off.
Why SA needs to have a concave window, I don't know. Personally, I'd like to see all device manufacturers put a 1/8" jack on the back and be done with it. Standardize it so it needs a stereo plug, 5V max input and maybe a flashing emitter on the face of the device, to confirm that a command reached it.
If you shine a flashlight on the face of most devices, the IR sensor can be seen. Obviously, some actually have a little white 'IR' next to the sensor but some don't even make it visible with a flashlight. In that case, it usually takes a bit of trial and error to find out where the emitter needs to go.