Features: The motor adopts punching shell,low-noise rolling bearing and it has a long service life; The structural parts adopt high quality punching sheet steel; The steel is of high-quality, light weight. It's beautiful and dignified in appearance; easy to install; CAD optimized design; Large air volume, low noise and stable working; Different sizes of 10",12",14",16",20",24",total 6 models. Available options: with extra shutter, with extra steel grill;