Wylex Plugs and Sockets

Old Wylex plugs and sockets, in unfused and fused 'ring main' types.
These have two flat pins and a very large round earth pin with a hollow centre.
Quite why anyone would have the smaller sockets fitted is a mystery, as all of the smaller plugs will fit into the larger sockets.
The larger plugs do NOT fit into the smaller sockets, so any house with only 2A or 5A sockets would be restricted to those ratings only.
The pin spacing on all types is identical, the only difference being the width of the L&N pins.
Website including Wylex booklet shown in the video: xo4.uk/?U32