The Wolf Tooth Seatpost Clamp is precision-engineered by Wolf Tooth to secure your seat post and serves as a great finishing touch with superb aesthetics. At the heart of the Wolf Tooth Seatpost Clamp are the custom self-aligning bolt and anchor. The M5 bolt includes a spherical washer and mates with a cylindrical anchor barrel. This means that threads are always perfectly aligned, preventing binding and ensuring consistent clamping force. Machined from 6061 Aluminum in Minneapolis USA, the Wolf Tooth Seatpost Clamp is available in four sizes and several colours. Wolf Tooth Seatpost Clamp Compatibility Clamping Diameter: 29.8mm/30mm 31.8mm/32mm 34.9mm/35mm 36.4mm 38.6mm/39mm Clamping height: 11mm Please Note: The seatpost clamp should match the diameter of the seat tube on your frame and not the diameter of the seatpost itself. Frame material can greatly affect the diameter of seat tube compared to the seatpost. For example, if the seatpost diameter on a bike with a carbon frame is 30.9mm it is very possible that you may need a 34.9mm seatpost clamp. Wolf Tooth Seatpost Clamp Specifications Weight:  29.8mm - 18g, 31.8mm - 19g, 34.9mm - 20g, 36.4mm - 20g, 38.6mm - 21g Material:  6061 T6 Aluminum, M5 stainless steel bolt with integrated washer Tool interface:  4mm hex key Torque spec:  6 Nm Max Made in the USA