Our QR seatpost clamp features a unique bushing that contacts the entire cam surface for the smoothest, most powerful action possible. The combination of a precision brass bushing and the smooth cam action of the lever makes for the most enjoyable lever experience. The brass bushing is precision machined to press-fit perfectly into the collar and mate with the lever cam. A custom Chromag 6mm bolt ensures reliability. CNC machined in Canada. (All Chromag frames use a 35mm)