I know this is designed for the Venge and Shiv seatposts in mind. The length is perfect, however the hard rubber surface that the light actually connects to and that keeps the light from moving around on the flat side of the seatpost isn't flat (or not wide enough), at least for the Venge, and results in the light being slightly off angled horizontally. Kind of annoying, not the end of the world and just a bit of tweeking should allow it to sit flush with the flat side of the aero seatpost. Maybe adding an additional layer of rubber between the seatpost and the strap will allow for a flush connection.