looked this up for you
There are two types of hose used within the Ion:
(two lengths) main hose: 4-mm outside diameter; 2.5-mm inside diameter.
(one length) solenoid output hose: 1/8" outside diameter, 1/16" inside diameter (or 0.060" inside diameter, if possible). This is the same type of hose that is used on Autocockers, Impulses with LPR, and other markers