A $material$ road sign.
(long for yellow iron)
This is what used to be a road sign back when the Highway Code was a thing anyone cared about. It used to be a low bridge sign judging by the colour and symbol - it would make a reasonable improvised shield, but it's probably not something to rely on in especially dangerous situations.
It is coloured $colour$ and is made of $material$ and looks like it could be held as a shield. It is in fairly poor condition.
It looks like it would be simple to repair.
Iron: 4000 grams
Steel: 4000 grams