Summary

When using the spool holder (version 2) (available here: https://wiki.creality.com/en/ender-series/ender-3-v3/quick-start-guide/printing-and-installation-guide-for-the-right-material-rack) without the "anti-tangle material rack," this filament guide reduces the risk of tangles and keeps the path directed smoothly in the correct path toward the runout sensor. It slips over the spool holder with no need for fasteners. You will need a piece of PTFE tubing about 20-30 mm long.

Installed and tested on an Ender3 V3 Plus-should work on standard Ender3 V3 as well. Not tested or intended for the KE or SE.