6907.21.10.11 - Tiles, the largest surface area of which is capable of being enclosed in a square the side of which is 30 cm or less

This HTS classification, 6907.21.10.11, specifically covers unglazed ceramic tiles and flags intended for paving, hearths, or walls, where the largest surface area can be enclosed within a square with sides of 30 cm or less. These are non-vitreous or semi-vitreous ceramic articles characterized by a low water absorption coefficient, not exceeding 0.5% by weight. The "unglazed" designation is crucial, indicating that these tiles have not undergone a glazing process after firing, which would typically create a smooth, impervious surface.

This category is distinguished from its sibling, 6907.21.10.51 ("Other"), by the specific nature of its "other" designation within the unglazed, low water absorption criteria. While both fall under the broader umbrella of unglazed, low water absorption tiles of a certain size, the distinction likely lies in more granular classification criteria not explicitly detailed at this level but resolved by further customs review or specific product characteristics that deviate from the primary sub-classification of 6907.21.10.11.

As this is a leaf node in the HTS structure, there are no further subcategories. Therefore, classification within 6907.21.10.11 requires that the imported goods meet all the preceding criteria: they must be ceramic flags or tiles for paving, hearth, or wall use; possess a water absorption coefficient not exceeding 0.5%; be unglazed; and have a largest surface area capable of being enclosed in a square with sides of 30 cm or less. Examples could include certain types of quarry tiles or unglazed porcelain paving stones that fit these precise specifications.