The new SL-K SBS SB20 seatpost is lighter and stiffer than ever – just 221 grams for the 27.2 x 350mm length. Using a UD carbon shaft with a bonded alloy head and a sophisticated MTC clamp design, we can achieve what we believe is the finest SL-K seat post yet. Available with a polymer Di2 battery holder. FEATURES UD Carbon shaft with bonded alloy head Forged alloy Top Clamp Chromoly Hardware UD carbon finish Black graphics