ct25664bc1339 crucial 2gb ram

You should check Crucials site for specs on that ram Your iMac needs exactly; 204-pin PC3-10600 (1333 MHz) DDR3 SO-DIMM if it's a mid 2011 or

204-pin PC3-12800 (1600 MHz) DDR3 SO-DIMM if it's a late 2011. Putting the wrong spec ram in a Mac will likely cause kernel panics or startup problems.

I "think" thats PC ram from Crucial. It's not the ram Crucial recommends for a 12,2 iMac. It might work but you could be risking possible kernel panics if it isn't right. Could be ram made by Crucial for sale by another vendor thus the different part number. Are you interested in buying this ram or do you already have it?