These printers use the W2123X cartridge:
HP Color LaserJet Enterprise M-554 DN
HP Color LaserJet Enterprise M-555 DN
HP Color LaserJet Enterprise M-555 X
HP COLOR LASERJET ENTERPRISE FLOW MFP M-578 C
HP COLOR LASERJET ENTERPRISE FLOW MFP M-578 E
HP COLOR LASERJET ENTERPRISE FLOW MFP M-578 Z
HP COLOR LASERJET ENTERPRISE MFP M-578 DN
HP COLOR LASERJET ENTERPRISE MFP M-578 F
HP Color LaserJet Enterprise MPF M-578 DN
HP Color LaserJet Enterprise MPF M-578 F