A keyring is the cheapest way into a set of coin replicas, and it is the version people actually use daily. The five coins are brass castings from traditional moulds, on a proper 304 stainless split ring — worth noting, because a plated steel ring will rust through within a season.
The brass will dull, which is normal and can be reversed with a cloth. No age, no numismatic value: these are reproductions and the listing says so.