... ,with CE certificate Portable ventilator(portable blower,air blower,exhaust fan) Size:8" 10"12" 14"16" 18" 20" Colors:yellow ,red, ... blue, ect.Main material: shutter: 7pcs dia-cast aluminum alloy,fan body ... novel design,special manufactured for underground cable maintainance,shipping making,exhaust for fire fighting, piping construction and in other violent ...