"Filament Spool Clip by vladaz320" is very small and useful clip.
But I felt a little difficult to handle.

I am sensitive to touching a sharp edge, so I wanted to make something a little more round.

The point that I devised a little is having put the slit in order to raise elasticity.

[news]
I made a 2nd version clip. so please check it and compare the two things.
https://www.thingiverse.com/thing:3680172