**Tri-color Optical Fiber Sub-duct** (also known as PE sub-duct or communication sub-duct) is a protective conduit for communication optical (electrical) cables, primarily made from **high-density polyethylene (HDPE)** or a blend of high/low-density polyethylene materials, formed through a single extrusion molding process. Its name derives from the **multi-colored stripe design** often applied to the tube body—such as red, green, and blue—which facilitates the identification of cables with different functions, enhancing the convenience of construction management.

? II. Core Features and Performance Advantages  

1. **Excellent Physical Properties**  

- **Lightweight and High Strength**: Light in weight, strong impact resistance, resistant to acids, alkalis, and corrosion(e.g., soil chemicals, humid environments).  

- **Flexible and Smooth**: Low friction coefficient on both inner and outer walls, minimal cable-pulling resistance, capable of curved installation, adaptable to complex terrains.  

2. **Long-lasting Durability**  

- **Service Life Exceeds 50 Years**: Anti-aging formulation ensures long-term stability in buried environments.  

- **Wide Temperature Adaptability**: Operating temperature range from -40°C to 60°C, suitable for extremely cold or high-temperature regions.  

3. **Comprehensive Safety Protection**  

- **Electrical Insulation**: Insulating material prevents leakage risks, ensuring circuit safety.  

- **Flame Retardant and Waterproof**: Self-extinguishing when exposed to fire, waterproof and moisture-proof, resistant to rodent damage.  

4. **Efficient Construction**  

- **Coiled Supply**: Standard length of 300 meters per coil (some specifications can reach 1500~3000 meters), reducing joints and simplifying installation.