Mains Switch Cover

This is the only thing I have found that I can make that will actually sell.
It can't be patented, the idea was covered by a patent that expired a long time ago. I have made well over a hundred of these, they used to cost 25p each to make and sell very well on Ebay for £1. They don't tend to sell well above £1.
THIS IS NOT TO PROTECT CHILDREN.
THIS IS TO PROTECT EQUIPMENT FROM CHILDREN.
The design looks strange, but that is because I searched for information on every mains socket I could find then used the data gained to make this design that should fit every available Mains Socket.
This is version 4, previous versions were simpler in design, but could get returned due to not fitting. This design has never been returned.