Heat Shrink Sleeve 30mm Black 1meter Industrial Grade WOER (HST) are excellent for insulation. They have exceptional insulation characteristics, excellent stress control properties; long-term weather and regular wear and tear resistance, ease of installation, and reliable performance even in the harshest of situations. These High performance 2:1 heat shrink material tubes, bundles, and protects cables; wire and hoses are for a wide range of DIY applications. It is used extensively for cable and wire harnessing, strain relief, insulation, color-coding, identification, and protection. Simply a great way to create a Flexible, Heat Resistant, and Waterproof tight joint. Just slide a slightly larger tube at the desired location and apply heat through a cigarette lighter, or a heat gun; for about 10 seconds and the tube will shrink down and will hold the joint tightly.