The things that replace a star nut and bolt all the way through the steerer. Might be worth it on downhill bikes but any point in putting one on a trail bike. About to get some new Revelations to go on a 456. Should I just go for the good old SFN instead.

Use it on one of my bikes, haven’t gotten around to using in on my others – handy for stopping mud going up the steerer.

Had a look after some use and it’s not wet/damp/muddy up there.

I see no point, all it does is pulls the headset into the crown race.

However i see the benefits, you don’t need to rely on the stem to keep it all tight, some stems clamping design isn’t as affective as others, and you get a bright spangly steerer bung..

they can be useful if you have a stem that doesn’t clamp particularly well – eg some expander wedge designs – but not really necessary otherwise

i don’t even bother with them on the DH bike anymore.

Used to use them but aside from the initial faff when fitting, a star-fangled-tangler works just as well and is far lighter.