With so many on offer recently, it is wise to have a name you can trust. The Ventline (7") 50 CFM Ceiling Exhaust Fan is certainly that and will be a superb buy.
Ventline Ceiling Exhaust Fan. Powered ceiling or bath fan, very efficient for smaller areas. Consists of the following parts: cap and roof flange assembly (sold separately). The power unit (motor, fan, and pipe assembly).
Inside grille is 10 inch Diameter Self-closing foam damper opens and closes. Dynamically balanced polypropylene blade will not bend out of shape. 8 inch Diameter rough-in opening required. 7 inch Fan without Cap and Flange, 115V, 50CFM.