This is an OMRON E5CC-CX3A5M-000 / E5CCCX3A5M product, which is new old stock (NOS). Linear current output control. No box as was built into a control unit that wasn't used. Datasheet here. https://files.omron.eu/downloads/latest/datasheet/en/h177_e5_c_e5_c-t_digital_temperature_controller_datasheet_en.pdf?v=1
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