The Royal Mint of the United Kingdom, which makes the country's circulating coinage, is also very active in the bullion coinage space and issues many bullion coins which are legal tender.
Additionally, it also makes bullion which is not legal tender and is targeted at investors and not at coin collectors - such as this one.
The Royal Mint says about this product:
"This 1 oz gold bar contains one troy ounce of 999.9 fine gold and is designed to personify the link between The Royal Mint and Britannia. For this range, the Britannia design has been newly interpreted by The Royal Mint’s Coin Design team and brought together by Principle Designer Jody Clark. This flat-edged 1 oz gold bar is imprinted with a unique serial number and is supplied in sealed packaging to securely transport and store your investment."
The type of packaging described above is referred to as "in assay" by bullion dealers.
The bar is "minted" (struck using minting techniques similar to a coin, and not cast in the way that larger investment products are).