SK HYNIX HMA851S6CJR6N 4GB 1RX16 DDR4 SO-DIMM PC4-19200 2400MHZ Laptop Memory at Amazon.com
Beware of the single rank x16 RAM kits sneaked in some laptop models! The 1Rx16 modules have significantly lower bandwidth compared to the 1Rx8 variants - NotebookCheck.net News
4GB DDR4 1Rx16 PC4-19200, PC4-2400T (BUS: 2400MHz), SK Hynix, Model: HMA851S6AFR6N-UH N0 AC, Notebook Memory or RAM module, Voltage : 1.2V, Non-ECC Unbuffered CL17 260-Pin SODIMM - WIT Computers