The cover paid the 40 naye paise airmail (printed matter?) rate from Fujairah to Argentina. I have also seen 40 naye paise rated covers to the USA, and to Canada, as well as a 20 naye paise rated airmail cover to England.
The date on the cancel is 21 Aug 1964. I have also seen a cover dated 20 Aug 1964.
The cover is franked with two 20 naye paise overprinted stamps from the British Post Offices in Eastern Arabia series.I am still checking for the earliest known date of use for this Fujeira cancel.
Unlike the Michel Stephen proposed stamps, these stamps do not have "Fujairah" overprinted on them. The hexagonal cancel would seem to indicate that the Fujairah cover was sent by J & H Stolow Inc. and may have included an announcement of the first series to be issued by Fujairah.
The service was a fulfillment of part of their 1964 contract with both the Fujairah and the British Governments to publicize the stamps of Fujairah.