Vortex Powerfans VTX12XL Fan V-Series 2050 CFM, 12" Extended collar and lip; allowing easy duct hook-up Aerodynamic design allowing more air flow Heavy gauge steel casing with a hammertone powder coat finish; making it more sound absorbing and rustproof High quality maintenance-free balanced motor, equipped with a mixed flow impeller, allowing extremely quiet operation 100% speed controllable, easing air flow adjustment and allowing better balancing of the ventilation system