2. IP68 waterproof brushless DC motor--seamless protective housing; high speed over 1000 rounds per minute; reliable lifespan more than 10 years
3. Engineering nylon+fiberglass compound fan blades with aluminum alloy frame--7 pieces cover wide area and produce even air circulation
4. detachable galvanized steel fan base--can easily take the fan apart by loosing 4 screws, fixing the fan base first makes the installation lighter and more flexible
(might upgrade to aluminum type that can be cut and shaped for different roof types)