air duct Light weight Oil,Acid,Alkai&high temperature resistant&fire-retardant PVC Good price,fine quality,satisfying service Air duct ... to 60" stander length:5m or 10m4,Main color: yellow,red,orange .white,black,green ect.5,Character: enduring high temparature ... , laboratory ,air-conditioner,engine room, the municipal conduct engineering,fire-fighting to ventilate or exhaust waste air,dust to supply ...