Difference between 461-AAEM and 461-AAEN TPMs for G14?

I'm shopping around for a TPM 2.0 chip for my R6515, which I can at minimum uses the G14 TPM line. However, I'm seeing mixed options of the 461-AAEM vs 461-AAEN. 

Which of these is best for the R6515? I think 461-AAEM is the official part based on another unit I have with a TPM, but I'm also finding that part hard to find online (brand new), whereas CDW has 461-AAEN's in stock (labeled as usable in R540 and R440).... So if I can use the 461-AAEN without issues in my R6515, that would be ideal, but would be nice to know before putting money down on a non-returnable part. 

Thanks!
Dan