Sonis alarm

I first came across the Sonis alarm from an advert in the June 2024 issue of the CAMC magazine, page 41 possibly, it retails at £420 INC VAT
What is unusual about this alarm it works on the principle of there being a sound signature when someone attempts a forcible entry. It is claimed to be suitable for home and motorhome use.
I have no connection or involvement with this company. I don't need another alarm and anyway if I did I would need to see independent reviews of this product first.

https://noentrysystem.com/

'Sounds too good to be true'

Here is another product in a similar vein  https://vanguardian.co.uk/ 
I have fitted this to my van and it works, the advantage of this product is that it will alarm before any damage is done