Raychem RT-375 is a clear, non-adhesive heat shrink tubing commonly used in professional wiring looms to protect labels and identification markings.
It is not typically used as the main outer covering of a harness. Instead, RT-375 is usually cut into short sections and applied over printed labels near connectors, sensors, or branches in the loom.
If you’ve ever seen a clean, professional harness with clearly labeled connectors, there’s a good chance something like RT-375 was used to protect those markings.
What Is Raychem RT-375?
Raychem RT-375 is a transparent heat shrink tubing designed for applications where you want to protect printed or written identification while still keeping it visible.
It is commonly used in:
- Motorsports wiring looms
- Aerospace and aviation wiring
- High-end custom harnesses
- Serviceable looms that require clear identification
Because it is clear, it allows the label underneath to remain readable after shrinking.
Does RT-375 Have Adhesive or Glue Inside?
👉 No
Raychem RT-375 is non-adhesive lined.
That means:
- no glue inside
- no adhesive flow when heated
- no sealing function like adhesive-lined tubing
Its main job is label protection, not sealing.
What Is RT-375 Used For?
RT-375 is typically used to cover and protect labels on a wiring loom.
For example:
- a label near a connector that says Air Temp
- a branch labeled Fuel Pump
- a section marked for identification during service or troubleshooting
Once shrunk over the label, RT-375 helps protect it from:
- abrasion
- oil and fluids
- heat
- dirt
- UV exposure
This helps the loom stay readable and serviceable over time.
Why Label Protection Matters
On a simple harness, labels may not seem critical.
But on a professional loom, clear identification makes a big difference.
Proper labeling helps with:
- faster troubleshooting
- easier service work
- cleaner documentation
- more professional finished appearance
If a label smears, wears off, or becomes unreadable, it makes future work much more difficult.
That’s where RT-375 becomes valuable.
RT-375 vs DR-25 — What’s the Difference?
This is one of the most important distinctions to understand.
Raychem RT-375
- Clear
- Non-adhesive
- Used in small sections
- Protects labels and identification
Raychem DR-25
- Black outer loom covering
- Non-adhesive
- Used as the main outer layer of a harness
- Protects against abrasion, fluids, and heat
👉 In simple terms:
RT-375 protects the label
DR-25 protects the loom
They are not interchangeable for the same job.
When Should You Use RT-375?
RT-375 is a great choice when:
- you want to protect printed labels
- serviceability is important
- you want the loom to look professional
- the harness will be exposed to fluids, abrasion, or UV
It is especially useful in:
- motorsports
- high-end street builds
- marine wiring
- industrial harnesses
- any loom where long-term identification matters
When RT-375 Is Probably Not Necessary
If the harness is:
- very basic
- temporary
- not labeled
- not intended for future serviceability
Then RT-375 may not be needed.
It is most useful when you are building with long-term durability and organization in mind.
How RT-375 Is Typically Used
In most cases, RT-375 is:
- cut into short sections
- placed over a printed label
- shrunk carefully to protect the identification underneath
This gives you a durable, professional-looking label that stays readable.
Final Thoughts
Raychem RT-375 is a simple product, but it serves an important purpose in a professional wiring loom.
It is best used when you want to:
- protect labels
- improve serviceability
- keep your harness organized
- give the loom a cleaner, more professional finish
If DR-25 is part of what protects the loom itself, RT-375 is part of what protects the information on it.
Need Help Choosing the Right Heat Shrink?
If you’re not sure whether you need RT-375, DR-25, ATUM, or SCL for your project, we’re happy to help.
📧 sales@ksvlooms.com
📞 1-888-725-5711