Cross Linked polyolefin tubing is much stronger than PVC tubing and will not burn like PVC. * Heat activated adhesive lining provides impervious seal to salt water, oil, acids, and sunlight as well as providing strain relief. * Nylon insulator, preferred by experts, for Marine Grade resistance to sunlight, water, oil, chemicals, vibration and cut-through damage. * Highest shrink ratio - shrinks to 1/3 original size.