I have Crucial 16GB Kit (2 x 8GB) DDR3L-1333 SODIMM Memory for Mac in my early 2011 Macbook Pro. I now have a new to me mid 2012 MacBook Pro. The 2012 calls for DDR3L-1600. Can I run the DDR3L-1333 in the 2012 without harming the computer?
No, the memory is not compatible as the MBP 2012 needs the faster 1600MHz memory and the 2011 is only using 1333MHz.