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 ColorBlackDiameter27.2Length350MaterialAluminumOffset (mm)0 Ritchey WCS 1-Bolt Seatpost Seatpost UPC: 796941416344