1,18" 20",24" 26",30" five different size 2,Strong Wall Bracket 3,cast iron motor body 2011 wall mounted ventilating fan(FB-D) 1,Telescopic adjustment a high degree of freedom2,Large air volume and low noise3,Motor with a long service life4,Strong Wall Bracket5, 18", 20",24" ,26",30" five different size;6, Suitable for heat-stroke prevention and cooling-down temperature in factories,workshop and ...