This adapter allows a Katadyn BeFree water filter to screw onto a regular water bottle threading similar to the popular Sawyer Squeeze water filters.
PLA is NOT recommended as it leaks water far more easily. I have found that Polymaker PolyMax-PC (formerly PC-Max) provides far better watertightness and recommend it.
Extruder Temp: 255C
Bed Temp: 80C
It is far better to print with more perimeters than higher infill, as it is concentric extrusions that increases watertightness. On Cura Lulzbot edition I was printing with 2 perimeters and 2 internal walls, which results in the central print column being entirely perimeters.