The Race Face Ride XC Seatpost is constructed of 6061 butted aluminum that is 3D forged, anodized and shot peened for strength and to keep the weight down. The head is a low profile 2 bolt design that is easy to adjust and works well with today's lightweight saddle rails. 27. 2, 30. 9, and 31. 6mm diameter sizes Black 295 grams (claimed 27. 2mm) 375mm length XC and Trail use | Race Face | Ride Xc Seatpost | Black | 27. 2Mm, 375Mm | Aluminum