Guardian Polysteel Vertical Rope Lifeline Assembly - 130 ft.UV resistant lifeline lasts longer This vertical lifeline is UV resistant, which means it won't deteriorate or lose strength from the sun's ultra violet rays. Needless to say, it doesn't tan well. However, your lifeline will last longer and you won't have to replace it as quickly or at all. Won't lose strength when wet The Guardian vertical lifeline does not absorb water, therefore it stays stronger in wet and damp environments (like fungus). In fact,