The Ritchey WCS 1-Bolt Seatpost features the patented SideBinder clamp desing that uses a single 5mm bolt for quick, secure adjustment.SideBinder clamp uses a single 5mm bolt to secure the saddleWide saddle clamp reduces stress on lightweight saddle railsWorks with all saddles with available clamp kits (ST3282, ST3283)Item SpecificationsClamp StyleStandard RailsColorBlatteDefined ColorBlackDiameter31.6Length400MaterialAluminumOffset (mm)20 Ritchey WCS 1-Bolt Seatpost Seatpost UPC: 796941416337