General Description: FirelineŽ is a pre-waxed, braided cord consisting of gel-spun polyethylene which is known as the strongest fiber, per diameter, ever created. It has an unbelievably high tensile strength & has been recommended in numerous how-to articles on beadworking. The 4 & 6 lb. tests will fit a #12 English beading needle. The 4 lb is like size B Nymo thread. The 6 lb compares to the size D Nymo thread. The 10 lb FireLine is used for projects using size F Nymo thread. Color is crystal White.