Tie-down fittings. Help please.

[Tony1963]

We’ve recently taken delivery of a 2017 Mercedes Sprinter van, on lease, to allow us to move tools and equipment between two airfields. The van is Luton spec.
In the back of the van, on the sides, are fittings as shown below, that could make our job safer if we had the hooks/eyes to fit.
Nobody here has any experience in this field, so I was wondering whether anyone could point me in the right direction for the fittings we need to make lashing down the cargo a lot safer.



Cheers

[Tony1963]

Thank you very much. That saves me wasting time looking for the wrong thing!