Opti-Brite's exclusive Rhino-Kote increases abrasion-resistance up to 50% top-grade twine twisted from 100% filament nylon. Elasticity absorbs sudden shock loads that would break ropes of other fibers. Resistance to rot, abrasion, mildew, marine growth, petroleum products and many chemicals. Opti-Brite colors are neon, easily seen in bright sunlight or dim areas where standard mason line can be hard to see. Spliceable, must be bound or fused on end to prevent raveling. Warning, not recommended for uses where personal safety is involved.