The precision-engineered Wolf Tooth Seatpost Clamp secures your seatpost and looks good doing it. At the heart of the Wolf Tooth Seatpost Clamp is a custom self-aligning bolt and anchor. The M5 bolt includes spherical washer and mates with a cylindrical anchor barrel. This means that threads are always perfectly aligned, preventing binding and ensuring consistent clamping force.Features-M6 stainless steel bolt with integrated washer-Tool interface - 4mm hex keyItem Specifications-Material:Aluminum-Type:Bolt-On-Color:Black-Diameter:39.7-Defined Color:Black