WF-30: 300mm, 100W, 1400r/min, 32m3/min; WF-35: 350mm, 170W, 1400r/min, 52m3/min; WF-40: 400mm, 230W, 1400r/min, 71m3/min; WF-45: 450mm, 280W, 1400r/min, 86m3/min; Beautiful outlook, longevity, more air delivery, lighter weight, easily installation & maintance and other advantages