Hey,
There will be two different types.
From the B4 the longest is 0.4" (Approx 10.16mm)
(Link:
http://www.teamassociated.com/parts/details/6278/)
These have an imperial 4-40 thread.
From the TC5/6.
There is a 10mm ball stud, this will have an M3 thread.
(Link:
http://www.teamassociated.com/parts/details/31285/)
I've the one for the B4 in stock.
MiCk B. :-)