yes, it is the 13A fuse. It isn't forced and fits perfectly. I dont think I would fancy running a kettle or heater off that smile This socket was fed from the local lighting circuit with a BS3036 15A fuse at the fuseboard and it is designed for a round BESA box but was not fed in conduit, just twin and earth. Dont know why but lots of stuff was like that.

I did look for a 240V clock to utilise the socket but could only find ones the size of Big Ben! We have just capped off the supply at high level.

Unfortunately we are lacking in the old socket stuff here, we dont get more interesting than 2A and 5A round pin sockets (which are still in use)

I took my time, I hurried up, The choice was mine, I didn't think enough