Here are the UMC box variations from right to left being earliest to latest. On the right, notice “twenty-five” is written out, and has a green label. These are blank on the back.
2nd generation keeps green label but changes wording a little bit. These are blank on the back.
3rd generation keeps same wording but makes the label more blueish, and also adds the warranted and guaranteed paragraph on a back label.
A 4th variation has a UMC-REM over-label sticker and I have seen this on just the 12mm.
Also, all of these should have the boxes with the “blanks” red sticker like this (The following is not my box.):