Our fan is Weight balance type exhaust fan (drop hammer type exhaust fan) 1, Mirror designed Stainless steel balde,with big air volume,never distortion and broken, the angle of the blades is patented designed 2, Galvanized steel sheet ,the layer of galvanizations more than 180 g/©O,one-off moled frame. 3, experiment of homeostasis make the blade work smoothly,nearly no noise and steadily output of air 4, Belt pulley are aluminium magnesium alloy injection moulded ,light and high-strength 5, Adopt auto belt-tensioner which can adjust the loose or tighten of belt and never drop 6, Imported france bearing with long service life Model specifications blade mm Blades rotational speed rpm Motor rotational speed rpm Air flow m3/h Total pressure Noise decibels Import power Rated voltage High mm Width mm Thick mm AM-780 710 960 960 23000 75 ¡Ü70 550 380 780 780 420 AM-830 720 660 1400 22000 60 ¡Ü60 550 380 830 830 400 AM-900 750 630 1400 28000 65 ¡Ü65 370 380 900 900 400 AM-1000 900 610 1400 30000 70 ¡Ü70 750 380 1000 1000 400 AM-1100 1000 600 1400 32500 70 ¡Ü70 750 380 1100 1100 400 AM-1220 1100 460 1400 38000 73 ¡Ü70 750 380 1220 1200 400 AM-1380 1250 439 1400 44000 56 ¡Ü70 1100 380 1380 1380 400 AM-1530 1400 325 1400 55800 60 ¡Ü70 1500 380 1530 1530 400. The size of the fan: 1380mmx1380x400mm Packing : standard exporting paper carton Weight : 76KG.