This Corsair DDR3 memory http://www.amazon.de/Corsair-zertifiziert-Laptop-Arbeitsspeicher-CMSA16GX3M2A1600C11/dp/B009EH010E/ref=sr_1_1?s=computers&ie=UTF8&qid=1422665066&sr=1-1&keywords=so-dimm+ram+16gb
DEFINITELY YES!!
I bought the same Memory for the same IMac 21.5" late 2013 EMC 2638, I teared down my computer and placed two 8GB RAM to reach the maximum and works perfect.
Good luck and buy them without any fear.