What is this? Pic included.

[ChetChet]

Cleared the attic and found two of these. They are really, really heavy.
15cm long
7 cm wide
2cm thick.
Note the hole in the corner. Are they weights of some kind - what for though?

Could be used to weigh down anything. I used to work in a theatre and they had similar weights tied to the curtains.

What would you say I should do with them? Charity shop or....?

If they’re metal, put them on the drive for the local scrap metal people.

Could be weights for diving bags, tent pegs, tarpaulins, virtually anything.

If they were mine, I'd keep them as they might come in handy for something. No idea what they are though, curious.