Device supplied with an imported item in a feeble attempt to comply with the law.
Electrical appliances sold in the UK must be supplied with a BS1363 plug already fitted, which will contain a suitably rated fuse.
This is defined in The Plugs and Sockets etc. (Safety) Regulations 1994 so at the time of making this video, had been a requirement for the previous 19 years.
The purchased item was an aquarium air pump. It was obtained from a seller on eBay, and the item was supplied from a UK warehouse.
When it arrived, the pump had a 2 core mains flex with a 2 pin plug moulded to the end. There is nothing wrong with this plug when used in the country it is intended for, but is it useless for anyone in the UK.
Clearly the seller was aware of the regulations, as an adaptor to convert the 2 pin plug to a UK type was included in the box.
The larger black adaptor plug shown in the video is the correct method if an adaptor must be supplied - that one is the correct size, has insulated pins of the correct dimensions, contains a fuse and is securely fixed to the 2 pin plug. It is fixed together with a screw, so that it cannot be accidentally removed.
The best option is to supply the proper BS1363 plug moulded onto the flex - the cost of doing that would be far less than a separate adaptor, and the box the product was supplied in was easily large enough to contain the proper plug.
In this case, the 2 pin plug was cut off and a BS1363 plug with 1A fuse fitted instead. However some people would not be able to do this, or be unaware of the problems in using the supplied adaptor