Hard white plastic plug with a 2A fuse.
The solid brass pins are unsleeved, as this plug is at least 40 years old.
A single screw in the centre secures the lid. Two smaller screws are for the flex grip.
Terminals are marked L N E and additionally by colour - Red, Black, Green. As these colours were not used in flex from the early 1970s onwards, this plug is 1960s or earlier.
Empire WT TO BS 1363
Pins are identified with L N E and the smaller screws with GRIP SCREWS