Berkley Fireline Thread is incredibly strong and thin and does not stretch or tangle. Diameter is 0.008" (0.20mm) equal to size D Nymo. Fireline is a pre-waxed, braided cord and one of the strongest materials made. Designer's choice for stringing and weaving projects - threads effortlessly and holds up well to beads with sharp or rough edges. Fireline has UV protection to withstand sunlight.