This two-coin set is part of a range of Royal Mint sets which include "historical" (i.e. not new) coins.
The mint says about it:
"The coronation of His Majesty King Charles III marks an important moment in the history of the British monarchy. As part of the celebrations of this national event, we have curated a range of historic coin sets that explore how His Majesty The King is connected to a royal story that stretches back centuries."
The set features a UK 50p coin from 1969, the year of His Majesty King Charles III’s investiture as The Prince of Wales - which was also the first year of the denomination’s issue, and a special coin from 2023 commemorating the coronation of the king, with his crowned portrait developed specially for the coronation commemorative range.
The 2023 coin is in Brilliant Uncirculated grade; the 1969 coin is circulated.