2:1 shrink ratio with waterproof performance - Shrink ratio 2:1; when heat is applied, shrinks to about one third of its original size, improving resistance to stretching and vibration and increasing tensile strength. Double-wall design for reliability - Two-layer construction with an inner lined layer that provides a waterproof, sealed connection and durable protection. Flame retardant and low smoke - Made from polyolefin material; flame retardant with minimal smoke. The fusible inner layer supports operation across -67 to 125 °C. Easy to use - User-friendly application: slide the tubing over the connection point and apply heat; professional insulated joints in seconds. Specifications and suitability - Material: polyolefin with an inner sealing layer - Shrink ratio: 2:1 (shrinks to about one third of original size) - Temperature range: -67 to 125 °C - Applications: ideal for sealing and insulating electrical connections in automotive, marine, outdoor, and DIY electronics projects Use scenarios - Automotive wiring: protect splices in engine bays from heat, moisture, and vibration for a durable, weatherproof seal. - Marine or outdoor installations: seal and insulate connections for lighting, pumps, or sensors against water and corrosion. - DIY electronics and home projects: quickly create waterproof, professional-looking insulated joints on exposed wiring.