Niue, a sovereign state in free association with New Zealand, uses two official legal tender currencies. The New Zealand Dollar is the circulation currency for daily transactions, while the government also authorises legal tender coins in the Niue Dollar currency for collector's purposes.
A number of mints issue a large variety of commemorative, bullion and collector coins under the authority of Niue. These coins are dedicated to historical or general popular culture themes not related to Niue itself. Many of them are in standard bullion sizes, based on the troy ounce - such as the half ounce of silver format (abbreviated as 1/2 oz Ag, where "Ag" comes from the Latin word for silver, Argentum).
This coin was issued as part of a four-coin set commemorating Czechoslovak airmen who fought as part of the Royal Air Force (RAF) during World War II, and pays tribute to Josef František.
The Mint says about it:
When the Luftwaffe launched the so-called "Blitz", which means a series of night bombing raids on English towns in September 1940, the Royal Air Force had no effective defence. The night pilots need to have good eyesight and a good dose of luck. The results of these risky actions, of course, did not match the effort, and therefore they began to quickly develop night fighter squadrons equipped with specialised technology - the on-board radar that was invented in Britain. Night fighter squadron RAF number 68 was established on 7 January 1941 and the first Czechoslovaks joined it in July of the same year. During the Second World War they fought not only against German aircraft, but also ships and missiles.
The fates of Czechoslovak aces were different - some fought in France, others were given the opportunity to shine in the sky above Great Britain. Some of them fell in battle, others returned to their homeland. Finally, their leaders turned their backs on them. However, their courage will never be forgotten. | 
Search for Niue: Silver Half Ounce 2017 Czechoslovak Airmen - Josef František on eBay 
