in thinking this is blooming dangerous?

[Dutchesss]

I'm looking for car seat covers on ebay and found came up with these;
www.ebay.co.uk/itm/Child-Baby-Accessories-Protector-Car-Seat-Belts-Adjuster-Safety-Triangle-Clip/283438156657?hash=item41fe3b0b71%3Am%3AmRw-SNzsQAZJw_woepl3RCA&LH_BIN=1
Surely the positioning of the seat belt being off of the childs hips would mean they are likely to be injured in an accident?
Why are these for sale?

A child wearing that would have serious abdominal injuries in a crash. How is it allowed to be on sale in the UK (or anywhere for that matter?)

It looks really dangerous, I just hope parents have more sense. There are hundreds of them for sale.