The WCS Alloy 1-Bolt Complete Clamp Set is designed to replace worn or damaged Ritchey 1-bolt seatpost clamps. This clamp set includes the entire seat clamp assembly, so all you need is the Ritchey 1-bolt post. The kit is surprisingly simple to install and easy service. These clamps are designed to be used with Ritchey Alloy 1-bolt post only. Make sure to choose the correct rail size for proper fitment to you saddle.