Does against older older anti-tank weaponry (it's official name is slat armor), but does not really work against Javelins and other modern weaponry. It's pretty much installed to calm down the soldiers.
I believe you're much more likely to be hit with some sort of older soviet rocket or drone dropped grenade than a more modern one such as Javelin. I see slat armor on Ukrainian vehicles too so I assume it's better than nothing. Now that I think about it I might actually have even seen a cope-cage on top of a Challenger tank too but I might be wrong on that.