Yes, the Lexar Professional 1667x 64GB SD is compatible with the OM System OM-5.
Lexar Professional 1667x 64GB SD is V60 class. Meets the floor for: 4K30 (30 MB/s floor). (Peak write 120 MB/s is not evidence of sustained performance; the V60 class rating above decides this.)
“OM System OM-5 product page: 4K 30p at up to 237 Mbps; V60 UHS-II SD card provides sufficient write performance for 4K recording.”
Last verified:
Compatibility inferred from spec rule (citations above are manufacturer-verified)