Build in a D-Shaped design for optimized aerodynamics and compliance. With three post lengths and two setback offsets, there is a post for all frame sizes and riding positions. Please note, the Aero Seatpost is built specifically for ENVE Melee & Fray frames. Developed in CFD and the wind tunnel, the Melee & Fray have features such as the d-shaped seatpost and refined tube shapes that have been tuned to complement our own SES(TM) rim shapes and deliver aerodynamic performance that is Real-World Fast(TM).