In addition to the standard seatpost bracket for the TraceR there are two other options.
TT Saddle Rail Bracket
This saddle rail bracket is designed to be used during time trials, allowing the light to be hidden under the seat. It will fit any standard rail design saddle.
Aero Seatpost Bracket
The aero seatpost mount allows you to fit your TraceR to all aero seatposts.