SpecificationSize: 2.5x1.5x1.6 mm (outside diameter x inside diameter x length)Color:BlackMaterial:Copper nano rings2.5mm：Nano ring nano beads for hair extensionHow to useThread the micro ring onto the threading hook;Take a small amount of hair and slide the micro ring onto your own hair strand by hooking it onto the threading hook;Slide the micro ring onto your scalp;Clamp the ring shut with the pliers.