So I learned something new today, thought I would share in-case others weren't aware.
We all know the Exactra 19 & 20 (and the TI-2000) have the bubbles we want for a screen-accurate lightsaber, 7 nice clear bubbles. The 21 & 22 have 9 bubbles.
Other calculators DO have bubbles as well, while NOT screen accurate
TI Business Industrial (normal and "I")
some commodore, HP and rockwell calculators have the lens strip
even the TI-little Professor
However, I'm beginning to think, not all Exactras have a bubble strip
I opened mine up, and there was nothing, just the red smooth LED Stick. The DATA MATH website matches what I've found in their internal picture
So...my mistake, I saw the data math big picture which looks like there could be bubbles in there. The ebay picture included a dark screen with no light shining through. I didn't catch on until I looked closer at DATA MATH (thank youu whoever wrote that website) I've started looking up anything on the bay there, to confirm bubbles if I want something real but not screen accurate. Still searching though, we all learn one way or another
EDIT: Exactra 22 has the same issue, no bubble strip!