Stupid question alert....

What's an FCU? (Acronyms escape me sometimes....)

Fused Connection Unit.

And if that hasn't jogged your memory, it is a device the size of a single
socket outlet that combines some or all of the following features.

1. A switch (optional)
2. An indicator light (optional)
3. A fuse (compulsory)
4. A flex outlet on the front (optional).

Christian.