WWI Eisernes Kreuz Zweite Klasse (EK2) / Iron Cross second class.
The ring on top that is attached to the ribbon is period replaced and has another small extra ring added. This was done very well.
The cross is in the ring maker marked with “KO”, but the crosses’ core does in my opinion not resemble a KO core. The core is more flat, as it appears typically with maker CD800.
An interesting cross for sure, with period replacement ring.