Professional grade military spec flexible polyolefin tubing provides excellent electrical insulation, protection from dirt, dust, solvents, and foreign materials as well as providing strain relief. Over expanded tubing easily fits over the end of wires and connectors and shrinks down to 33% of it's original diameter for a snug water-tight protective seal without a reduction in the tube's original length.Hi-Temp Shrink Tubes can be used to insulate wires, wire splicing, connections, terminals and meets the material functional properties of Military Spec DTL-23053/5C. 3:1 shrink ratio Operating temperature range: -67°F to 275°F Apply at 120°F to 180°F using a heat gun