This method uses no bond/glue/heat braiding or sewing in or chemicals - Previous methods for hair extensions would be harmful for the hair, also causing discomfort or pain. Size:Size:4.5mm(outer diameter)*2.5mm(inner diameter)*3.0mm(length) Quantities:1000units per color per bottle,net weight:about 62g. The silicone lined can protect your hair out of any hurt and can hold your own hair more tightly.prevent the stick hair extensions falling off from your head. Color of the Silicone lined same as the Silicone Nano beads in order to give you a more invisible feels. The extensions will last several months, depending on how fast your own hair grows. Eventually, the micro rings will have to be removed, or moved up towards the scalp again. We use the excellent silicone pipe to make it.