Phat Filter, 6" x 20", 450 CFMPhat Filter uses high grade and low density carbon to eliminate the nastiest smell and particles from your grow area. You can also use it to ventilate your shed, home, barn, etc. This high performance filter is the preferred choice by plenty of indoor growers and hobbyists. It has a cylindrical shape for easy transportation, Mongolian virgin charcoal for maximum absorption, and other great features. Made with a High Grade Charcoal: The air filter is