If anyone is having difficulty locating the correct plug for the EPS output (it appears that installers "forget" to leave this item after an install), then you can obtain them here:
https://www.alibaba.com/product-detail/ ... 30386.html
It might take a few weeks, but they're very cheap (£2.34) with free shipping (typically).
In my case, I did ask Fox where to get one, and eventually they asked for my address. Nothing has arrived as of yet.