The 150mm Manhole Chamber Base with 4 Inlets is a versatile underground drainage component designed to connect multiple 150mm diameter pipes within an inspection chamber system. Manufactured from durable polypropylene, it features four inlet ports—typically two at 45° and two at 90°—allowing flexible pipe configurations for efficient flow management. This base is compatible with Polysewer risers and 470mm chamber riser rings, forming a complete inspection chamber for foul or surface water drainage.