The O'Brien Siege is a streamlined ski that's designed to deliver speed and stability. This is the same shape found on the popular O'Brien Sixam 2.0. With a tunnel concave, edge changes are smooth and effortless. A softer flex and increased rocker make the Siege feel stable right out of the box. Small defined bevels mean faster, easier turns. Adjustable ARC fin. Pro Wing foil not included.