What am I?

This hitchhiker came with my last coral. I know its some sort of worm but cant figure out exactly what it is. There are two in the picture if you look closely a larger one and a smaller one right next to it, the tube is a very thick hard calcium buildup and when they retract inside ( at lightening speed) they pull some sort of cap over the opening.

 

Feather duster. Harmless filter feeder.

 

I know its a feather duster but wasnt sure what type, most of the hitchhiker ones I see are all white this one has a different shape and some color to it

 

its a "RED" feather duster

 

Think I found an ID
Pomatostegus stellatus- star horseshoe worm