This is meant to block a lot of ambient light, which the Saturnus v6 seems really sensitive to.  It doesn't make the Saturnus great, but it does make it ok.

Friction fit.  Includes cutout for charging port.

Orienting on its back as in the second picture makes for no supports.  You can support the charging port cutout if you want, but I didn't bother.  Nothing about that is dimensionally important.

2 perimeters at typical .45 extrusion width makes for no infill.

Any filament should work.  Even translucent filaments will probably block the IR the chrono depends on.