Please note - this item is on backorder until the end of May. You can order now and it will ship when it is back in stock. Experience the benefits of a whole house fan even if you have little or no attic space. This roof mounted fan is great for applications that cannot use a standard whole house fan such as a manufactured home, home with a flat roof or a home with a sealed attic. This roof-mounted fan includes the RM WHF-4.0 Fan, 2 Damper Ceiling Grilles, RF Wireless Control Kit, Cut-out Template and Accessory bag. This fan requires no minimum attic clearance and can cover 1181 to 1771 square feet. Features: 3 speeds Ultra Energy Efficient Electronically Commutated Motor (ECM) RF Wireless Control Kit Included 15 year warranty Built in the United States More Info Ideal for homes with flat roofs or little attic space. Download the Roof Mount Whole house Fan with Damper Grilles Specification Sheet Download the Roof Mount Whole house Fan with Damper Grilles Installation Manual Includes:  RM WHF 4.0 fan; 2 Damper Ceiling Grilles, RF Wireless Control Kit, Cut-out Template and Accessory bag Specifications Airflow (CFM): 3543 High/3205 Medium/2878 Low HVI-916 Airflow (for CA Title 24 New Construction) (CFM): 2730 High/2390 Medium/2100 Low Energy Use (Watts): 451 High/316 Medium/219 Low Speeds: 3 Minimum Attic Clearance: None Dampers: 2 - Barometric Pressurized Dampers 14” x 14” Motor Head Diameter: 24.75" Motor Voltage: 120 Vac, 60 Hz Roof Opening: 22" circle Framing: Roof Rafter - 24" on center; Ceiling Joist - 24" on center Minimum Suggested Attic Venting: None Damper Grille Outer Dimension: (2) 16" x 16" Ceiling Rough Opening: (2) 14.25" x 14.25" Warranty: 15 year