Used Crucial 4GB CT51264BC1339 MT16JTF51264HZ-1G4M1 So-dimm
Specs
Capacity 4GB
PC3-10600
DDR3-1333
204pin So-Dimm
Fits:
Apple iMac 21″ Mid 2011
Apple iMac 27″ Mid 2011
Apple MacBook Pro 13″/15″ 2011
Apple MacBook Pro 13″/15″ 2012 (Non retina)
Fully tested working part