PC12800 DDR3L 1600MHz SO-DIMM 4GB for 2011-2015 iMac, 2011-12 Mac mini, and 2011-2012 MacBook Pro (non-Retina display) models
Original 4GB Apple SO-DIMM removed from an iMac 27" Late 2014 (separate listing for other parts)
Used and tested in functioning iMac. Comes in sealed plastic case inside padded envelope for protection.
I have two (2) of these -- $10 per SO-DIMM.
For your safety and mine, cash only and meeting at a CVS or Walgreens during the day where funds can be immediately deposited through bank's Add Cash In Store program to ensure against counterfeit before RAM is handed over. Inspecting in store beforehand of course fine.
Willing to meet buyers at any CVS/Walgreens in the Bay Area, but price will increase to cover gas/bridge tolls for anywhere other than Half Moon Bay.
If interested in delivery or another payment method, the SO-DIMMs are listed bundled on eBay -- ask for the link.