Cardas XLR-RCA adapters FXLR-MRCA (XLR Female/RCA male)
These adapters not only sound very good (fuller and richer sound than cheaper adapters) but they are also super sturdy. Even the ones that connect directly to cinch outputs are so strong that they can handle dangling a heavy cable from them without bending.
Used only once or twice and in 100% optical new state and of course technically also 100%.
Also see my other ad for a variant on these connectors.