This is a great WWI Iron Cross second class single mount (Ek2 Einzelspange).
The cross is in the ring maker marked with maker “KO”, this stands for maker Klein und Quenzer.
In good condition and with a lovely blueish backing! We have it’s twin brother but in the form of a non fighters variation (Nichtkämpfer) with the same very rare backing in our shop as well. Simply a lovely single mount Iron Cross in a very rare configuration and backing!