Aerodynamic Posture 1 is the most forward pelvic rotation, common in triathlons. Split support zone eliminates soft tissue pressure for a more powerful rotated position. Saddle nose structure is designed for stable and symmetric pedaling. Strategic dual layer foam provides soft top layer for comfort and firm base for support. Oversized carbon rails and Channel Flex on bottom of shell for added compliance. inForm BioDynamic products optimize your natural movement for sustained, higher performance. Available Speed Storage system securely holds water bottles, tube, and inflator. Requires oversize rail-compatible seatpost and seatpost ears.