AiteFeir DDR3 Desktop Memory PC DIMM for ALL 240PIN 1.5V 16GB (2X8GB)1866MHZ PC3-14900 Computer RAM 8GB (2 x 4GB) DDR3 1866 (PC3 14900) - Newegg.com
dosdude1 on X: "Just finished upgrading a friend of mine's 2015 11” MacBook Air from 4GB of 1600MHz RAM to 16GB of 1866MHz RAM! Now, of course, it runs a whole heck
Is a 1600mhz RAM motherboard forward compatible to accept 1866mhz RAM memory? - Quora