Gitzo’s Center Ball Heads are extremely balanced and versatile heads, engineered and designed focusing on ultimate smoothness and precision of the movement and locking. GH1382QD is the medium-sized head, designed for Series 0 and 1 Mountaineer tripods, and also fits between the folded legs of Series 2 Traveler tripods. Despite its slim design, it is fully featured including the friction control knob positioned inside the ball locking knob.It is supplied with the short, Arca-Swiss compatible plate (GS5370SD), but is also compatible with all of Gitzo's D profile plates and fits most Arca-Swiss style plates from other brands