My god when I remember, I searched this little part 2 hours once in house, on knees with magnifying glass before 4-5-6 years

He jump over my head who knows where in room... And I found him... I found him! I scream as lunatic...
My friend remove that ring from 5-6 fans, he put fan in plastic bag and his head and hand inside bag and easy with tweezers remove him.
And if ring jump he is close....
Best fan ever made, only need to be re-paint because default look very bad. And it's very hard to remove dust from blades even with alcohol once if become dirt.
I stop to use them because of that. CORSAIR fans are much easier to clean.