Another 13A fused 3 pin plug, this one with three flat blades in a row, the earth blade being 90 degrees to the other two.
Pictures sent in by Simon, who writes: These were installed throughout the house where I lived in during the 80's.
Rated 13 amps, 250V. This could be connected to a standard ring circuit in the UK, which was fused at 30 amps.
The interior has a fuseholder for a 13A or lower rated fuse, this connected in the centre L pin. Neutral connection on the lower pin, and earth on the upper pin which has an angled tip and is longer than the others to operate shutters inside the socket.
Flex grip is a flat bar secured with two screws, a very common design used in many other plugs.
'1285' is either the model number or possibly just a reference for the moulding.
The recessed edge of the socket would fit into a panel or front cover plate.
Earth pin at the top, line centre, neutral bottom.
A single screw secures the lid of the plug, with the flex grip screws concealed when the lid is in place.
Other plugs (mainly round pin) used before the ring circuit was introduced did not normally have fuses, and it was common for the 'new' ring main plugs to have the word 'FUSED' on the outer cover.