Later Le dynasty, Le Hien Tong (1740-1786 AD), Canh Hung era (1740-1786 AD), 'Canh Hung Noi Bao', simplified 'Bao'. 3.4g, Bronze, 23.71mm. Canh Hung coins with many type of varieties, some are very rare but most are common. This 'Noi Bao' variety is significant undervalued in Krause and also lots of related research under-estimated its rarity. In Japanese annam coins study, it's grade 2 (very rare), what do you think? I think it's grade 6-7 (scarce/slightly scarce). Crude cast very fine.