There is no physical or different features of the SanDisk microSD A11M and E11M.
The first letter seems the country where the card is suppose to be distributed and sold (for each Market) . Those letters were used by SanDisk in the past, now they have been replaced for an only letter for all markets.
The meaning was:
SDSDQ-032G-A11M : America
SDSDQ-032G-E11M : Europe
SDSDQ-032G-P11M : Asia
Currently SanDisk changed the end letters and now they are using the same for all country markets. (i.e. -U46 / -X46 , etc…)
Regarding the difference between Nokia or SanDisk, just go for a SanDisk one. SanDisk cards are quite better and cheaper than Nokia. If you need extra speed just go for the newer microSD Ultra UHS-1 30MB/s version.
Ciao!
