Yes, the Lexar CFexpress Type B Professional Gold 128GB is compatible with the Nikon Z6 III.
Lexar CFexpress Type B Professional Gold 128GB is VPG400 class (certified 400 MB/s minimum sustained write), clearing Nikon Z6 III's 250 MB/s requirement for 4K60 (Nikon's own manual states this as a raw sustained-write floor, not a class rating). Type B slot confirmed on Z6 III.
“Nikon Z6 III product page: Dual Card Slots — SD UHS-II + CFexpress (Type B)/XQD; CFexpress Type B cards supported in the dedicated CFexpress/XQD slot.”
Last verified:
Compatibility inferred from spec rule (citations above are manufacturer-verified)