My Omni 546 which has digital readout is stenciled on the rear, HF Transceiver Model 546 Series C. It also has a serial number tag which has 546-4189 on it. So while it does not say Omni D series C, it is digital which is what the D stood for, it is an Omni D (digital) series C, and is still the best cw rig that I have used. 73 Paul K9OT