OUTERDO Bike Seat Post 3K Carbon Fiber Mountain MTB Bicycle Seat Post Road Cycling Alloy Pillar Seatpost Material: Carbon fiber (3k Weave) Size: 27.2/30.8/31.6*350mm With the special design,the carbon fiber seat post can save for a long time Carbon fiber tube with full carbon head is the pinnacle of lightweight performance and strength One bolt design offers easy fore-aft and infinite angle adjustment