The Black Inc Carbon Road Seatpost comes equipped with outer rail clamps for 7x9mm oval rails, which are nearly always carbon. If you plan to use a 7x7mm round rail saddle, you will need the proper Outer Rail Clamp Set. Or if you simply need replacements, just select the size you need.

The outer rail clamps simply sit outside the wedge pieces that insert into the post. Black Inc's hardware, consisting of a bolt, washer, and receiving nut; then are used to clamp the four pieces together, the wedges and outer rail clamp securing the rails of you seatpost. The hardware and wedges that come with the Carbon Road Post are be used regardless of the saddle rail diameter and shape.