LK Levin's King Hair Building Fiber are 100 % Natural Product is available in natural shades. Levin's King Hair Building Fibers, made of colored keratin protein, blend undetectably with existing hair strands to instantly create the appearance of naturally thick, full hair. WHAT IT DOES Instantly fills in thinning areas. Conceals hair loss. Makes fine hair look completely thick and full. Great as a root touch-up between colorings. WHAT ELSE YOU NEED TO KNOW Levin's King Hair Fibers resist wind, rain, and perspiration for long-lasting results in all conditions. Available in Hair Fibers work for all hair types and textures. Also great for part lines, covering extension tracks and touching up roots between hair color appointments. Easily washes out with shampoo.