The Radius of Contour (RoC) describes the lengthwise curvature of the skate blade. It is sometimes referred to as the 'profile' or 'rocker' on the blade. Skates commonly have a single radius of contour (eg. 9 foot, 11 foot), but Blademaster contouring systems can optimize performance by applying multiple radii or more complex shapes to your skates, therefore giving you improved speed and agility.