1620 Max External Blower Cfm, For Use With Select Broan Range Hoods The Broan Elite External Exterior Range Hood Blower For Broan-Nutone Hoods. The External Blower Is Designed To Help Exhaust Airborne Contaminants From Cooking And Living Spaces. Features Weather-Resistant Aluminum Construction To Help Provide Durability And A Removable Cover For Easy Maintenance, Mounts On A Roof Or Outside Wall.