These printers use the CF503X cartridge:

HP Color LaserJet Pro M-254

HP Color LaserJet Pro M-254dw

HP Color LaserJet Pro M-254nw

HP Color LaserJet Pro M-280

HP Color LaserJet Pro M-281

HP Color LaserJet Pro M-281cdw

HP Color LaserJet Pro M-281fdw

HP Color LaserJet Pro MFP M-280nw

HP Color LaserJet Pro MFP M-281 CDW

HP Color LaserJet Pro MFP M-281fdn

HP Color LaserJet Pro MFP M-281fdw