8GB Memory for Acer Aspire TC-780-UR17 DDR4 2400MHz Non-ECC UDIMM (PARTS-QUICK Brand) at Amazon.com
Amazon.com: PNY Performance 8GB DDR4 DRAM 3200MHz (PC4-25600) CL22 (Compatible with 2933MHz, 2666MHz, 2400MHz or 2133MHz) 1.2V Notebook/Laptop (SODIMM) Computer Memory Kit – MN8GSD43200-TB : Everything Else
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