95% of all solar ventilation (attic fan) products are sold with old styled motors which use brushes within the motors. Bottomline, you should know this because it does not matter. The warranty offered, they will wear out depending on the quality from 2 to 8yrs. So if a competitor offers you 20yr, 25yrs or lifetime the motor will fail before it reaches these years. Sure, some will send you a new motor but who is going to pay to replace it? THE CONSUMER WILL. Ask, most of the time manufacturers never mention the type of motor so you can be sure they are offering a brushed version.