FULLY hair building fiber is a kind of high-tech product which contains thousands of tiny fibers to attract with existing hair, just in 30 seconds to present a thicker and fuller hair look. Hair Building Fiber, it is also named hair fiber in short or hair thickening fibers with their function included. Because they are tiny fiber, so they are also called micro fiber, or hair fiber powders. They thicken hair very quickly, people like them as instant hair fibers, or instant hair growth. Before they are mainly made of keratin, they also have the name of keratin hair building fibers. Since more and more people pay attention to its safety so they are also called natural hair building fibers, or micro fiber natural hair fibers.