This is a unique fiber that glows in the presence of light. It is useful for decorative displays and Christmas displays as well as conventional communications applications. Fiber color extends through the entire fiber core. Standard stock item is 0.5 mm in diameter and is available in three fluorescent colors. (0.25, 0.75, 1.0, 1.5, and 2.0 mm diameter fibers are available upon special request.) Specify length when ordering (minimum is 2 meters).