This is a silver proof version of the mint set of Australian circulation coins issued in 2021. Unlike the sets in base metals, it contains the definitive "Aboriginal Elder" $2 coin and not a commemorative.
The Mint says about the set:
This stunning 2021 Fine Silver Proof Year Set comprises six beautifully manufactured fine silver coins featuring Australia’s iconic circulating designs enhanced with striking new frosting and polished finishes. The Royal Australian Mint has once again set a new benchmark in numismatic quality and attention to detail with this stunning set.