If you are looking for a way to make a cheap and easy air assist coil hose, you can make your own. Buy some 4mm I.D / 6mm O.D. pneumatic hose off of ebay(or somewhere else) Wrap the hose tightly around a small pipe and heat it with a heat gun. After heating, immediately cool the hose with cold water. The hose will hold it’s shape indefinitely. I also bought some 90 deg pneumatic fittings and a straight through hole fitting to make a clean looking install. all parts cost less than $10 US
thanks for your share!!
Very nice!