This cap works on most XLR ends, I made it specifically for DMX and it works with both the 3 and 5 pin variant. It would work perfectly for 3 pin XLR connectors for audio.

This will only fit on female cable ends!

To put it on line up the notch on the cap with raised edge off the connector. It will latch on like a cable. to remove you will need to press the cable release and pull the cap off. Exactly like removing a cable.