Original remixed from https://www.thingiverse.com/thing:4814083
and adapted to fit in the spool hole of XINGTONGZHILIAN PLA filaments.
It's only one adapter needed for every single spool.
You have to push the adapter from the front side (where the picture is on it) to the middle of the spool.
Because the spool hole is conical (at least mine) it will be tough enough when the middle is reached.