For use with powdered chalk for marking between two points to give a straight line. Braided line resists fraying, and is also useful for a plumb line as it does not spin round as conventional twisted cord. Braided nylon has less stretch than other lines and is also the strongest. Braided Nylon chalk lines are ideal for most applications in the building industry. This Braided nylon line is particularly suitable for bricklaying as it is stretch resistant. Length: 18M This listing is for TWELVE bundles Size B is thicker than Size A