Hair length?

There is a thriving world market in cut human hair of sufficient length for wig manufacture and for the production of training materials for student hairdressers and barbers. In less developed countries, selling one's hair can be a significant source of income — depending on length, thickness, condition, and colour, wig makers have been known to pay as much as US$40 for a head of hair. In the United States, cut hair of at least 10 inches (25 cm) length may be donated to a charity, such as Locks of Love.