Feather dusters

[booya]

OK I rolled some of my rocks in my tank over and I found some sort of feather dusters. I was wondering if all feather dusters OK or if some are bad:nervous:

 

[fender]

AFAIK all dusters are safe and cool.
I have a bunch in my tank, small red ones, white ones with red spots, and a ton of small brown ones. No problems.