36" Belt Drive Whole House Fan With Automatic Shutter, Pulls Air From A House Size Of 2300 SQFT, 6900 CFM, Runs On High & Low, 2 Speed Wall Switch Included, Needs 1325 SQIN Of Open Exhaust Vents In Attic Space, Rough Opening Is 34-1/4" x 36-3/4", Automatic Shutter Is White, Do Have To Cut Joist When Installing Fan, With Motor Mounted On Struts Above Housing, Fan Will Be Quieter Than Direct Drive Models, 10 Year Limited Parts Warranty, 5 Year Limited Labor.