So, to avoid the inner air flow tube design flaw of the EWI 5000, I blocked the inner tube and added an external tube that I can replace at will. Probably will replace once every few months as needed. We’ll see. My first EWI 5000 clogged up completely after 12 months. This is a prototype. This is purely a proof of concept. Notice the exit is at the top of the octave rollers. This has the added benefit of constant moisture on the rollers, creating a more secure electrical contact between the rollers and your thumb.