A-Tech 16GB Module for HP EliteBook 840 G4 Laptop & Notebook Compatible DDR4 2400Mhz Memory Ram (ATMS266635A25831X1) at Amazon.com
Kimtigo DDR4 16GB Laptop Dram 2666MHz (PC4-21300) CL19 (Compatible with 2400MHz or 2133MHz) 1.2V Notebook (SODIMM) RAM Non-ECC Unbuffered Single Rank 260 Pin PC Computer Memory Module Upgrade at Amazon.com