Safety Hooks for roof (bed safety net)

I think a bit more info would help,as i expect there are many hooks that could be used 

Not an easy task, you have to resize them - there are free apps, can you post a photo of existing sort? Plus the actual situation of  where and what for? If that makes sense!

Yes, Heres a photo, it was too large to attach but worked it out! The safety net has a clip which clips onto the link. Thankyou.

You might be able to identify the part name by using Google lens, Cortana etc or right click on the image to find similar products.

That is not a caravan specific item.  Hardware retailers probably have them in wee packets of two or so.  It may be faster to go and take a look than trying to figure out what they are called !

This item on e-Bay is very similar:-  234160678016.

Knowing that children are heavy and caravans are built from little more than compressed paper, I would need to be convinced that the fixing is safe. Preferably bolted through something substantial with a big spreader on the reverse side.

It's to prevent a child rolling out of the bed inadvertently. It's not the same as a "lee cloth" in a yacht bunk that has to cope with sudden movement. A relatively light hook would, IMHO, suffice. Probably be able to make one from a coat hanger.

Smaller versions of the one in the photo can be used in picture framing to attach string or wire, places like screwfix, bq will stock various sizes, hopefully.