The Ancor Adhesive-Lined Heat Shrink Tubing Kit includes 4 pieces of 3/4" diameter tubing in an assortment of colors - yellow, white, blue, and green. Cross Linked polyolefin tubing is significantly stronger than PVC tubing and won't burn like PVC. The heat-activated adhesive lining shrinks at 257° F (125° C) to provide an impervious seal against salt water, oil, acids, and sunlight, as well as providing strain relief. Ancor Adhesive-Lined Heat Shrink Tubing provides the highest shrink ratio you'll find anywhere, shrinking down to a third of its original size. Operating temperature range: -40° F to 230° F (-40° C to 110° C). UL 224.