Fan/Duct/Filter Size: 4 Inch Airflow: 205CFM Noise: 26.8dBA Controller Type: Speed Controller & APP Smart Control   EC-Motor with PWM Controlled The Mars Hydro iFresh 4-inch inline fan is equipped with a PWM-controlled EC motor, ensuring growers achieve efficient and precise fan speed control, ultimately optimizing performance. This motor offers a longer service life compared to AC motors, enhancing safety and operating at a remarkably low noise level. Airflow up to 205 CFM Enjoy the advantages of robust yet silent ventilation with the 4-inch inline fan, running at a fan speed of 3000 RPM and providing an impressive airflow of 205 CFM. This significant airflow capacity ensures suitability for various grow tent sizes while enabling rapid temperature and humidity control. Energy-Saving & Low-Noise The fan operates at a voltage range of AC 110-240V, incorporating energy-saving technology to ensure efficient and quiet operation. This design allows for effective ventilation without compromising energy efficiency or causing disruptive noise levels in your grow space. Temperature and Humidity Smart Regulation The iFresh inline fan features intelligent regulation capabilities, enabling growers to define a "safe range" for temperature and humidity. In response to conditions falling outside this range, the fan automatically operates at maximum speed, ensuring a consistently optimal climate within the grow room. App Intelligent Control Connect to the Mars Hydro APP for convenient OTA remote control and access to smart features, including alarms, climate triggers, and loop timers. With just a few clicks on your smartphone, adjust fan speed, control on/off functions, and automate device schedules. It provides growers with effortless and precise management of their grow space.