ADATA 8GB Premier DDR4 2400MHz 260-pin SO-DIMM Laptop Memory Single (AD4S240038G17-S) 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