4:1 Adhesive Heat Shrink Tubing 12mm – Glue Lined Waterproof Sleeving

Measure the total cable run or splice area you need to cover, then add at least 10–15% extra for overlap and trimming. For a single wire splice, 1 metre (≈39") is generally sufficient. For wiring harnesses or longer conduit runs, 5 or 10 metre rolls are more economical. As a quick reference: 25mm (1") of tubing typically covers a standard butt splice connector.

A 4:1 shrink ratio means the tubing shrinks to one-quarter of its original inner diameter when heat is applied. Starting at φ12mm, it typically recovers down to approximately φ3mm, allowing it to grip a wide range of wire gauges and connector bodies securely — without needing to stock multiple tube sizes for different wire diameters.

Yes. The inner adhesive lining melts during shrinking and flows around the substrate, creating a moisture-resistant seal. It is generally suitable for outdoor, marine, and automotive environments where moisture ingress is a concern. For fully submerged or high-pressure water exposure, confirm suitability with your specific application requirements before installation.

The 12mm inner diameter (before shrinking) typically accommodates wire bundles, connectors, or cable jackets up to about 11–11.5mm in diameter. After full shrink, the recovered diameter is approximately 3mm. Always measure your substrate's outer diameter before ordering to confirm the tubing will fit over it and recover tightly onto it.

Glue-lined polyolefin heat shrink tubing generally begins to shrink at around 90°C (194°F) and fully activates the adhesive at approximately 120–135°C (248–275°F). A heat gun is strongly recommended over an open flame for even, controlled shrinking — especially on sensitive electronics or near plastic connectors.

Yes. The adhesive-lined construction is commonly used in automotive wiring repairs, marine electrical connections, and trailer wiring because it resists vibration, moisture, and corrosion. Confirm that the operating temperature range of your application falls within the tubing's rated limits before installation in high-heat engine bay locations.

No. All five color options — Black, White, Red, Blue, and Transparent — share the same 4:1 shrink ratio, adhesive lining, and wall thickness. Color choice is typically used for circuit identification, polarity coding, or aesthetic preference. Transparent is particularly useful when you want to visually inspect the connection after shrinking.