3/8 inch Breathing Air Hose - TPR-375-50
Any of the fresh air you use must go through only a certified type of hose. This hose must be labeled for “breathing air line” or “fresh air line” otherwise you may be looking at safety fines in a job site.
Anything else may off gas and contaminate your breathing air.
This item i5 for 50 feet of 3/8 breathing air hose.