We have seen many hot tubs come into the UK with 'wooden box's' on the cabinet to house their stereo or DVD players. This cover allows either an amp for mp3 /phone connection, or the stereo/DVD to be mounted behind it (this is a cover and will not hold/mount your radio/dvd player) and not rot!
Include's a gold cable to connect to the front plate, then has a 3.5mm jack at the other end for connection to your headphone jack on say your iPhone.