reducer duct

1.Outside is elastic helix steel wire , inside there is a lay of aluminum foam

2.With the strong points of  heat wasting reduction,low wind resistance,good nosie elimination,energy saving,environment protection ect.

3.Easily to connect due to flexible

4.Enduring the high temperature and oleic acid

5.Schlep easily wherever exhaust and inhalation the air in the field condition due to light-weight

6.Prevent the workers from the suffocating by improving dust air into fresh air .

The diamater can depends on your requirement.