1.factory audit 2.material(aluminium,copper,silicone) 3.4.5mm,5.0mm are all available ... ok These micro rings have a coating of silicone inside. The silicone protects the clients hair from coming into contact ... rubs against it during the life of the extensions. Silicone is an 'anti slip' material, This means the ... : black,light brown,brown,dark brown,blonde silicone lined micro ring / silicone micro bead