... 1)wide rage sizes; 2)stable motors; 3)quiet, big air volume.. Cross Flow FanImpeller is made of Aluminum Alloy.The motor ... insulation class E, B, H.The blowers, creating high air volume with low vibration, are commonly used in HVACsystems, machinery for ... heating, ventilating, air conditioning, drying, dehumidifying,etc.Please contact us for more details