13A plug to 2x 13A sockets and one 5A round pin socket.
Made by Grelco. List No. K/135.
The pins are unsleeved due to the age of this item - sleeved pins were not required when this item was manufactured.
The small red piece is a fuseholder.
The holder is just a piece of red plastic - it has no electrical connections at all.
The internals are constructed on a printed circuit board. The 5A terminals and the 13A extension terminals are riveted to the board. The terminals on the back of the plug pins are secured with screws which also secure the pins.
The 5A fuse protects the 5A socket only - the 13A sockets are directly connected. This does mean that in theory, two 13A appliances could be connected, overloading the socket this adaptor is plugged into.
The four brass posts secure the brown plate over the shutters, and the top of each is threaded to accept the screws which secure the two halves of the adaptor together.
The brass posts also make contact with the earth tracks on the printed circuit board.