Polypropylene (PP) push-fit drainage pipe fitting.
Push-fit underground drainage system:

Compared to the solvent-gluing drainage system, EGIC produced the first push-fit underground system made of polypropylene to ensure ease of assembly and insulation. Our underground fittings include four internal ribs on both sides to tolerate heavy loads up to 8 KN/m2 and prevent dust from penetrating the drainage system.

The advantages of push-fit underground system:

Higher flexibility to tolerate ground movements and heavy loads up to 8 KN/m2 without damage
Effectively perform under high temperature that may reach 95°C
Prevent dust from penetrating the drainage system
Fully anti-leakage system and chemical resistant
Easier to fit, install and repair than alternative materials that need solvent-gluing
Push-fit fittings are easily removed so they can be repositioned as needed without specialized tools
Dimension