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. UL Listed and CSA Recognized Highest shrink ratio - shrinks to 1/3 original size. Shrinks at 257D F/125D C. Operating temperature range 40D C to 110D C. ANCOR heat shrink connectors offer heat activated adhesive built into the sleeve of the heat shrink tubing Shrinks to form a water tight seal and the ultimate vibration and strain relief. Tinned for corrosion resistance. Pure copper for maximum current flow.