“Socket covers affix to power sockets providing a dual layer of safety.” This is a straight lie, they simply plug into the socket just like other socket covers do! It is not possible to “fix“ a plug-in socket cover to the socket.
“The unique ‘anti grip’ design makes it difficult to remove without the use of a tool.” The anti grip design is a good idea, and essential if a socket cover is to be made difficult to remove, but the poor implementation and failure to make the pins the right size have resulted in a cover which is easy to remove!
“The Lindam Dual Locking Socket Covers have been developed to supersede like for like products, through design and rigorous testing.” To describe them as “Dual Locking Socket Covers” is simply not true, some retailers advertise them as “Lockable” equally untrue, they do have a lock symbol on the extraction screw in the centre of the cover, when the screw is turned the cover is pushed out, but it is NOT a lock! Your guess is as good as ours as to what the rest means, but it is very clear that the design is faulty, and they have not rigorously tested them.