Key benefits Reliable waterproof sealing: double-walled design with an inner adhesive layer forms a tight, moisture-resistant seal around wire joints and connectors. Strong, durable protection: 2:1 shrink ratio provides increased tensile strength and better resistance to stretching and vibration compared with standard heat shrink tubing. Fire-resistant and low smoke: made from flame-retardant polyolefin to reduce fire risk and minimize smoke in the event of a fault. Fast, easy installation: slide over the connection, apply heat, and achieve professional insulated joints within seconds. Main features Shrink ratio: 2:1 (described to shrink to one third of original size when heat is applied). Construction: double-walled with a heat-activated melt adhesive inner layer to ensure a sealed, waterproof bond. Material: flame-retardant polyolefin outer layer with a meltable adhesive inner layer. Temperature tolerance: withstands temperatures of -67 to 125.0 °C (-55 to 125 degrees Celsius). Performance: higher tensile strength and improved resistance to stretching and vibration versus normal shrink tubing; produces little smoke. How it solves common problems Prevents moisture ingress that can corrode connections or cause shorts by forming a bonded, sealed barrier. Protects splices and solder joints from mechanical stress, abrasion, and vibration that cause failures in automotive, marine, and industrial applications. Limits fire and smoke hazards by using a flame-retardant material that maintains insulation properties across the specified temperature range. Typical applications Automotive wiring repairs and splices: seal and reinforce connections on engine harnesses, sensors, and battery terminals exposed to vibration and moisture. Marine and outdoor electrical work: waterproofly insulate connections for bilge pumps, lighting, and navigation equipment. Home electronics and industrial equipment: protect soldered joints, terminal blocks, and cable transitions from mechanical and environmental damage. Usage instructions Slide the correct size over the joint or connector. Apply heat evenly (heat gun or appropriate heat source) until the tubing shrinks and the inner adhesive flows to form a seal. Allow to cool to obtain a durable, watertight connection. Compatibility and selection tips Choose the tubing diameter so that, after shrinking (2:1), it fits snugly over wires, splices, or connectors. The double-walled design is suitable for electrical splices, solder joints, terminals, and connectors in automotive, marine, industrial, and home applications. This product provides a durable, waterproof, flame-retardant solution for protecting electrical connections against moisture, vibration, and mechanical stress while remaining quick and simple to install.