certified genuine article; guaranteed authentic item
Refers to an item that comes with a certificate or guarantee of authenticity, often used for antiques, artworks, or high-value goods.
This tea bowl is a certified genuine article, and its box inscription is still intact.
Compound of 極め付き (kiwametsuki, 'certified, guaranteed') + の (no, possessive particle) + 品 (shina, 'item, article'). The term 極め付き derives from 極める (kiwameru, 'to ascertain, to verify') + 付き (tsuki, 'attached'), referring to a certificate or guarantee attached to an item.