My father says he had some aluminum/concrete forms that were stolen
(long story). He wants me to tell the police that they were indeed on
the property. The problem is that I have no idea what these look like.
I saw all sorts of building material but I don't know the names of any
of it. I tried doing a Google image search for "concrete forms" but
came up with several different varying pictures. Could someone please
direct me to some pictures of aluminum/concrete forms.

While we're on this topic, could someone tell me whether these
aluminum/concrete forms are generally more expensive than I-beams?
Those were stolen too but at least I found pictures of them through
Google.

Thanks to anyone who can help
Mike S.