8GB Dual Channel Kit 2x 4GB SAMSUNG Original 204 pin DDR3-1333 PC3-10600 CL9 DDR3 SO-DIMM for current i5 + i7 notebooks with DDR3-1333MHz support (electronics)
... Were in my iMac of 2011 4 previously there that 8 were also clean. Runs without difficulty for over a year, the Mac was at the time no longer than a few hours off, was perhaps five times booted and is otherwise gone through.