Metal cased version with space for 2 circuits.
In this example, the fuse cover has been cut away to allow a plug in MCB to be fitted. The other space is fitted with a blank.
The plug in MCBs have a plastic shield which covers the live busbar. These are similar, but not identical to the shields for the fuses.
Inside, the typical Wylex moulded plastic mechanism can be seen. The switch design is the most common traditional one, with the switch lever made from red coloured plastic. In this instance, ON is the UP position.
Incoming supply at the top, circuit neutrals connecting to the terminals bottom left. Earths to the brass bar fixed to the metal case at the bottom right.
As this assembly is only rated for 45A total, neither of the fuseways have the notch to allow high rated fuses to be fitted.
EIther rewireable fuses, cartridge fuses or plug in MCBs can be fitted.
Part number M132/4. Made in England.
There are four additional holes in the back, two of which are used to secure the inner frame. The other two suggest this box was used for a different configuration, possibly a single way switch.