AC Infinity Inline Duct Fan Silencer, 4-InchDescription Duct Muffler Design: This muffler is primarily used with inline fans in grow tents, bathroom fans, and other HVAC applications. The product features dual aluminum flanges that can absorb sound waves from fan vibrations and airflow, effectively reducing operational noise. Quality Material: It contains high quality neoprene foam arranged in an egg crate pattern. This aspect of design helps in reducing fan noise by up to 50%. Its galvanized