Park Tool 1971 Clamp Adapter For D-Shaped Seatposts Description: The Park Tool 11971 Clamp Adapter For D-Shaped Seatposts allows select Park Tool repair stand bike clamps to accept D-Shaped seat posts and seat masts with stable retention that will prevent damage to pricey components. Features: Clamp adapter for locking jaws found on Park Tool repair stands Useful for bikes with D-shaped seat posts or seat masts as well as other non-traditional designs Compatible with the following Park Tool repair stands: PCS-9.2 and PCS-9.3 PCS-10.2 and PCS-10.3 100-3D Micro-Adjust Clamp, as found on PRS-2.2, PRS-2.3, PRS-3.2, PRS-3.3, PRS-33.2 100-5D Micro-Adjust Clamp, as found on PCS-4 100-25D Micro-Adjust Clamp, as found on PRS-25 and PRS-26