Ritchey WCS 1-Bolt Seatpost: 27.2, 350mm, 0 Offset, BlatteThe Ritchey WCS 1 Bolt Seatpost features the patented SideBinder clamp desing that uses a single 5mm bolt for quick, secure adjustment. Product Details: SideBinder clamp uses a single 5mm bolt to secure the saddle Wide saddle clamp reduces stress on lightweight saddle rails Works with all saddles with available clamp kits (ST3282, ST3283) Specifications: Clamp Style: Standard Rails Color: Blatte Defined Color: Black Diameter: 27. 2 Length: 350