The WAHL Professional PowerDry Tourmaline Coated Grille refers to the special front grille on the Wahl PowerDry hair dryer that is coated with tourmaline, a semi-precious mineral. This coating helps the dryer emit negative ions during use, which lock moisture into the hair cuticles, reduce frizz and static, and leave hair smoother and shinier compared with ordinary dryers. The tourmaline-coated grille basically enhances drying performance and improves hair finish by promoting moisture retention and sleekness.