7z Hair

Less Common. In some Asian markets (particularly Korea and Japan), there is a specialized perm technique sometimes referred to as "Seven-S" or "7S."

Most Likely Scenario. In the world of hair extensions, hair is graded by quality using numbers and letters (5A, 6A, 7A, 8A, etc.). "7z" is a very common typo for "7A." 7z hair

, both are centered on the unique needs of tightly curled, high-maintenance hair. The Mystery of "Type 7" Hair Less Common