Whatever length 1/4" O.D. PTFE tubing I drilled a 3/8" hole in my cabinet for filament to run through. Fit the hose to the nipple on the funnel part, run the hose through the hole. Fit the other two pieces together using the key way, and clip on to the bushing on the top right screw of the ALU Extruder (v2). Measure out how much tube you want, cut it, and fit it into the extruder head end. Load filament through, take a step back and appreciate your hard work.