... 3,with CE certificate Portable ventilator(portable blower,air blower,exhaust fan) Size:8" 10"12" 14"16" 18" 20" Colors: ... novel design,special manufactured for underground cable maintainance,shipping making,exhaust for fire fighting, piping construction and in other violent working ... or welding, laboratory ,warehouse to ventilate waste air,harmful gas,dust ect. portable ventilator (exhaust fan)