Center ball heads are available in three sizes. The new center ball heads are also included in traveler tripod kits, as well as in mountaineer tripod kits. The slimmest in the range, designed to fit between the folded legs of Series 0 and 1 Traveler tripods. It does not feature the friction control knob, but features independent pan lock. It has no compromises in the ball smoothness (WS2 coating) and hardness of the external and internal components.