Upgrade your noisy, inefficient vent fan without replacing the entire vent or disturbing the rooftop seal. Just replace the existing screen and 12-volt fan with the high-velocity three-speed Vortex II Fan Kit to turn your roof vent into a powerful ventilation system. Enjoy over 300% more air movement over standard roof vents. Quiet operation with three forward speeds and two reverse. 9" fan blade. Easy installation with only a screwdriver. Universal fit for Ventline, Jensen, Heng's, and Elixir powered vents. White polymer construction.• 3-speed forward, 2 reverse• 9" blade• Universal retrofit• Quiet and powerful• High-velocity air fan system• Easy, quick installation with just a phillips head screwdriver• Easily replaceable without compromising the rooftop seal• Self-centering metal base with radius corners• Works with Ventline, Jensen, and Elixir powered U.S. vents• Vortex Fan Speed: 188 cfm 9"" fan blade Easy, quick, simple installation with just a screwdriver Works with Ventline, Jensen, & Elixir powered U.S. vents | Heng's Vortex II Vent Fan in White