2:1 Adhesive Glue Lined Heat Shrink End Caps — Waterproof Seal, 8–130mm, Black/Red/Green

Match the cap's recovered inner diameter to the outer diameter of the wire bundle or cable end you need to seal. The diameter listed (e.g., 8mm, 30mm) is the recovered inner diameter after shrinking. Before shrinking, the opening is typically 2× that size, so you have room to insert the cable. For example, a 30mm cap starts at approximately 60mm opening. When in doubt, size up slightly — you can always apply more heat to achieve a tighter seal. If you need to convert: 1 inch ≈ 25.4mm, so a 25mm cap is roughly 1", and a 50mm cap is roughly 2".

A 2:1 shrink ratio means the tubing shrinks to half its original diameter when heat is applied. For example, a cap listed as 30mm will start at approximately 60mm inner diameter and shrink down to around 30mm (≈1-3/16"), conforming tightly around the cable end. This ratio is standard for most general-purpose heat shrink end cap applications.

Yes. The inner adhesive lining melts when heat is applied, flowing around the cable end to create a moisture-resistant seal. These are generally suitable for outdoor, marine, and automotive environments where moisture ingress is a concern. For fully submersed or high-pressure applications, confirm suitability with your specific use case before installation.

Yes. The adhesive-lined polyolefin construction provides a weatherproof barrier that is typically suitable for outdoor wiring, automotive harnesses, marine cable terminations, and trailer wiring. The polyolefin material is generally resistant to UV exposure, oils, and common chemicals encountered in these environments.

These caps typically require a heat source of around 120–150°C (248–302°F) to begin shrinking, with the adhesive activating at similar temperatures. A heat gun is the recommended tool — apply heat evenly around the cap, working from the closed end toward the open end to push air out and ensure the adhesive flows fully around the cable. Avoid open flames, which can cause uneven shrinkage or scorching.

The color options are purely for identification and organization purposes — for example, color-coding positive/negative leads or different circuit branches in a wiring harness. All three colors share the same adhesive-lined construction and 2:1 shrink performance. Choose the color that matches your wiring convention or project requirements.

Each listing lets you choose 1, 5, or 10 pieces per order. For a single repair or prototype, one piece is sufficient. For ongoing projects, vehicle builds, or professional electrical work, the 5- or 10-pack offers better value per unit. Mix and match sizes and quantities to suit your specific job.