it's a
metric threaded fittings, most others are standard threading you can buy them at most paintball shops or online stores.
i'd just go with macroline (basically you buy fittings for each end then it uses a plastic hose.
this
http://www.sundragonpps.com/catalog/...46/6853450.htm
+
http://www.sundragonpps.com/catalog/...46/6853462.htm
+
http://www.macrolineguy.com/products...Macroline.html
you will have to cut the hose down to size though