With a PWM-controlled EC-powered motor and mixed-flow design, the Mars Hydro 4 inch inline fan delivers airflow up to 205 CFM quietly. Controlled by a digital touch-screen thermostat controller with a sensor probe, this 4 inch inline fan features “Environment Monitor”, “Timing Schedule”, “temperature/humidity alarm”, and “high/low temperature or humidity triggers” functions. It also provides other essential features — 10-speed adjustment to meet your ventilating requirements, controller lockout to prevent accidental triggering, calibration mode to modify the detected ambient data, screen brightness modification to protect your eyes in whether bright or dark rooms…Every feature is designed to make your indoor growing easy and happy, and to maintain a stable and consistent indoor grow environment.

The filter core is made of 1050+ activated charcoal imported from Australia to bring 100%-fresh air and eliminate odors, harsh tastes, and particles. The double-sided galvanized steel mesh provides 53% of the open area for airflow to pass through so that the odor absorption and elimination process can be carried out thoroughly. (The carbon filter was covered by a prefilter cloth; do not remove it when using.)