G.Skill F4-3200C16D-16GTZR Trident Z RGB Series 16 GB (8 GB x 2) DDR4 3200 MHz PC4-25600 CL16 Dual Channel Memory Kit - Black with Full Length RGB LED Light bar at Amazon.com
HP 8GB DDR4 SDRAM Memory Module - 8 GB (1 x 8GiB) - DDR4-2933/PC4-23466 DDR4 SDRAM - 2933 MHz - Unbuffered - 288-pin DIMM at Amazon.com
Amazon.com: Axiom 8GB DDR4 SDRAM Memory Module - for NAS Server - 8 GB (1 x 8 GB) - DDR4-2666/PC4-21300 DDR4 SD : Electronics
SAMSUNG M471A1K43CB1-CRC 8GB DDR4 2400MH Memory Module (8 GB, 1 x 8 GB, DDR4, 2400 MHz, 260-Pin SO-DIMM) at Amazon.com
Amazon.com: OWC 8GB (2 x 4GB) PC19200 DDR4 2400MHz SO-DIMMs Memory Compatible with Mac Mini (Late 2018), 27" and 21.5" iMac (Mid 2017), and Compatible PCs (OWC2400DDR4S08P) : Everything Else