Vent out or recirculating with optional charcoal filters (configured for both options) . Up to 760 CFM (cubic feet per minute) with 4 speed fan. 21-Gauge 430 Brushed Stainless SteelUnique design blends in with most workshop or garage settings. Fits ceiling heights 7 ft. to 12 ft. with optional chimney short kit or extension kit(s)