Kingston Hyper X Blu 8 GB (2x4GB Modules) 1600MHz DDR3 Non-ECC CL9 XMP Desktop Memory - KHX1600C9D3B1K2/8GX 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
HPE RAM Memory 1 x 8GB DDR4 SDRAM 8 DDR3 2400 SDRAM 759934-B21 at Amazon.com