Zipp sl speed seatpostthe zipp sl speed seatpost is based on their popular service course model it features the same high range of adjustability and a low profile clamping hardware as seen on zipps alloy models but with the added benefit of the stiffness and low weight of carbon fibre optimise your positionwith the sl speeds high adjustability range you can position the saddle exactly where you want it so you really can get the most out of every crank rotation also the low profile clamping