The Tjernlund PVC4 Inline Radon Mitigation Booster Fan is a compact, efficient solution designed to reduce radon levels by improving ventilation in residential systems. Measuring 4 inches in diameter, this fan moves air at 90 cubic feet per minute (CFM) and operates on only 16 watts, making it energy-efficient. https://www.partshnc.com/pvc4-tjernlund-products-pvc-inline-radon-mitigation-booster-fan-90-cfm-includes-6-power-cord-16-watt