Apollo Horticulture 4" Inch 190 CFM Inline Duct Fan with Built in Variable Speed Controller for Ventilation 1 - Apollo Horticulture 4" Inch Plastic Vent Inline Fan Dimensions: 11.8" x 8" x 7.6" / Duct Size: 4" / Ducts ends are removable Plastic inline fan with built-in adjustable speed control  keeps air cool and moving in your indoor gardening environment Versatile  great for grow rooms, greenhouses, kitchens, commercial and home spaces, industrial environments, factories, locker rooms, attics, bathrooms, warehouses, storage spaces and any area you need to assist your current air duct or ventilation system Quiet and durable fan increases airflow to help move chemicals fumes, smells and odors out of your space. You can always rest assured that you are backed by quality hydroponics equipment from Apollo Horticulture. / ** 1 YEAR MANUFACTURER WARRANTY **