This 4-inch inline duct fan pulls heat, humidity, and smoke out of enclosed spaces like grow tents, hydroponic rooms, electronics closets, kitchens, and basements. A high-efficiency copper motor spins at 2550 RPM to move up to 200 CFM at 165 Pa of air pressure, while staying quiet at around 29 dB thanks to vibration-dampening rubber mats, so it won't add noise to a work area. Manual knob control lets you adjust airflow speed to match different ventilation needs, from gentle circulation to a stronger pull. It measures 12 x 9.3 x 7.5 inches and weighs 4.4 lbs, and comes with hang-up slings plus non-vibration rubber mats and straps so it can be suspended in a tent or mounted flat on a wall in whichever orientation the space calls for.