43N Đặc Biệt is a special premium variety of traditional fish sauce produced by Ông Kỳ on Phú Quốc Island. It is made from fresh anchovies caught in the waters surrounding the island and sea salt from the Bà Rịa–Vũng Tàu region. Uniform anchovies of suitable species are selected during the period when they are at their optimal maturity. The fish and salt undergo natural fermentation for approximately 12 months in large traditional wooden barrels. After maturation, the pure first-press sauce is extracted without being blended with liquid obtained from the second and third extractions. The 43N designation indicates that the product contains approximately 43 grams of total nitrogen per litre. This is the highest natural nitrogen concentration permitted under the specification for traditional fish sauce bearing the Phú Quốc geographical indication. The sauce has a clear amber colour with reddish highlights and a pronounced but clean aroma of fermented anchovies. Its flavour is intensely savoury and rich in umami, with natural depth and a long, slightly sweet finish. It is made exclusively from fresh anchovies and sea salt, with no added sugar, preservatives, artificial colours or flavourings.