The underbrace connects the front two lower control arms. It’s the same as the Nismo power brace:
http://phase2motorsports.stores.yahoo.net/nispowbracs1.html
Except this unit attaches to the existing control arms, whereas the Nismo Power Brace is welded together. Both are functionally the same. With a FSTB, the brace, and some T/C rods the front end was uber-stiff.
The cluster bezel is still available.