The PT4 low voltage radon fan is the ultimate low voltage radon fan for many different jobs. This fan can handle the challenges of all different soil types. When pressure is low (multiple suction points, sub membrane systems, large porous sub-slab areas, etc.), this fan moves very high volumes of air. When the pressure is high (clay soil, compact sand, wet conditions, etc.), this radon fan is capable of very high suction. The high airflow and high suction capabilities outperform other low voltage radon fans in its class.