3:1 Heat Shrink Tubing — Unlined Weatherproof Sleeve, 1.5mm–6mm, 6 Colors

Measure your wire or connector's outer diameter before shrinking. Because this tubing has a 3:1 shrink ratio, choose a size that is typically 1.5–2× the recovered diameter you need. For example, 3mm tubing recovers to approximately 1mm, so it suits wires up to about 1mm OD. When in doubt, size up one step — you can always shrink tighter, but you cannot expand tubing that is too small.

Quick inch reference: 1.5mm ≈ 1/16", 3mm ≈ 1/8", 4.5mm ≈ 3/16", 6mm ≈ 1/4".

A 3:1 ratio means the tubing shrinks to roughly one-third of its original inner diameter when heat is applied. This is generally more versatile than standard 2:1 tubing because it can accommodate irregular shapes, connectors, and stepped transitions that a lower-ratio tube cannot conform to.

Yes. This tubing is designed to be weatherproof once fully shrunk. It typically provides resistance to moisture, UV exposure, and mild chemical splash, making it suitable for outdoor wiring, marine applications, and under-hood automotive use. For fully submersed or high-pressure water environments, we recommend confirming suitability with our team before ordering.

This tubing generally begins to shrink at around 70–90°C (158–194°F) and reaches full recovery at approximately 120°C (248°F). A heat gun set to low or medium is the recommended tool. An open flame can be used carefully but may cause uneven shrinkage or scorching if held too close.

Yes. The four diameter options cover a wide range of AWG wire sizes commonly used in US automotive, marine, and residential electrical work. As a general guide:

• 1.5mm — typically suits 26–22 AWG fine signal wires
• 3mm — generally covers 20–18 AWG
• 4.5mm — fits 16–14 AWG in most cases
• 6mm — accommodates 12–10 AWG power conductors

Always verify against your specific wire OD, as insulation thickness varies by manufacturer.

Color is primarily for identification and organization — for example, using red for positive leads and black for ground in automotive wiring. All six color options (Red, Yellow, Blue, Green, Black, White) share the same material properties and shrink performance.

Absolutely. The tubing is sold in continuous lengths of 1 m, 5 m, 10 m, and 20 m and can be cut cleanly with scissors or a utility knife before or after shrinking. Cutting at a slight angle can make it easier to thread over connectors before applying heat.