Measure the total length of the area you need to cover and add 10–15% extra for overlap and shrinkage. Available options are 1 meter (≈39.4"), 2 meters (≈78.7"), and 3 meters (≈118.1"). For battery packs, measure the full module length. When in doubt, order the next size up — you can always trim before shrinking, but you can't add length after the fact.

This tubing typically has a 2:1 shrink ratio, meaning it shrinks to approximately half its original expanded diameter when heat is applied. At a 420mm flat width, the expanded circumference is approximately 840mm. After shrinking, it will conform tightly around the target object. Always verify your pack's outer circumference fits within the expanded diameter before cutting and positioning.

Standard heat shrink tubing generally provides moisture resistance suitable for indoor and light outdoor use, but is not typically rated for full submersion or prolonged rain exposure. For applications in heavy moisture, marine environments, or outdoor installations, an adhesive-lined (dual-wall) heat shrink is generally recommended. Contact us to confirm the moisture rating for this specific product before purchasing.

Activation typically occurs between 90°C–120°C (194°F–248°F). A heat gun on a low or medium setting is the most reliable and consistent tool for large-diameter tubing. A hair dryer generally does not reach sufficient temperature for full, even shrinkage on wide-format tubing and is not recommended. Avoid open flames, which can cause scorching or uneven results.

At 420mm flat width, this tubing is designed for large battery modules and multi-cell pack assemblies — not individual small-format cells like 18650 or 21700. It is generally suited for wrapping grouped cell assemblies, bus bar insulation, or full pack outer sleeves in e-bike, power wall, or custom energy storage builds. For individual cell wraps, see our smaller-diameter heat shrink options.

No. Both Black and Blue variants are made from the same base material and offer identical insulation and shrink characteristics. Color selection is purely for visual identification or aesthetic preference — useful when color-coding different battery strings, circuits, or wire groups in a multi-pack build for faster identification during maintenance.

Yes. Cut the tubing with sharp scissors or a utility knife before applying heat. Cut slightly longer than your target coverage area, slide it into position over the battery module or wire assembly, then apply heat evenly from one end to the other. Once shrunk, the tubing cannot be repositioned, so confirm placement carefully before heating.